Kris

This page lists questions and answers that were posted by visitors named Kris.

Questions

The following questions were asked by visitors named Kris.

Where there is a math problem with different instructions like 15+6/3 and there are no parenthesis, which do I do first...the 15 + 6 or the 6/3? What are the order of operations when there are no parentheses?

How many states border oceans? My answer is 15. I didn't include the states like Texas that borders the Gulf of Mexico and Connecticut as it borders the Long Island Sound...is this correct?

Which is the smallest burrough in New York...Manhattan or Bronx?

Quick question: When writing CHRISTIAN CLUB is it Christian Club or Christian club? Thank you

The costs of doing business for a company can be found by adding fixed costs, such as rent, insurance, and wages, and variable costs, which are the costs to purchase the product you are selling. The portion of the company’s fixed costs allotted to this pr...

A book called The Penguin Dictionary of Curious and Interesting Numbers by David Wells (1986) contains fascinating numbers and their properties. One of which is the only 3-digit numbers that are prime and all rearrangements of their digit are also prime a...

What branch of the national goverment was designed to be the most democratic and responsive to the people?

A number has four digits. the sum of the first and last digits is twice the second digit. The second digit is 2 less than the third digit. The last digit is twice the first. Some of the digits are alike. what is the number??

What cellular process involves mitosis? Wouldn't that be (growth)

Can someone give me a website about Alexander the Great. A website that desrcibes who he is and what he did and how hes important....... thxx :}

In the article "A Nation Apart" Identify the thesis statement? What statagies does the author use to formulate his argument and what makes the argument so viable and compelling

when the sum of 5 and 6 is subtracted from the product of 5 and 6 what is the difference

terry shared three pizzas with some friends. terry ate 1/4 of them. how much pizza did terry eat?

Felicia traveled 7 kilometers to school 1/10 of that time she walked and 9/10 of the distance she rode a bus. A. How far did Felicia walk? B. How fare did she ride?

If all of the chemical potential energy stored in a 100 Calorie snack pack was converted to thermal energy and subsequently absorbed by water, what would be the final temperature of the water? Assume you have a 1.5 mole sample of water initially at 25 deg...

Help! Solve: 1. 3x + 15 = 0 2. 6x + 18 =0 thanks!

Rewrite the following as an equivalent logarithmic equation.Do not solve. Show your work. m^n=r

Given logb3 = 0.792 and logb5 = 1.161. If possible, use the properties of logarithms to calculate values for the following show your work logb 1/3

How long will it take for the population of a certain country to double if its annual growth rate is 1.5%? Round to the nearest year. Use the exponential growth model P(t) = P0e^kt

What happens to a 4L volume of gas as you change the pressure from 6 atm to 760 torr? What law was used, and show work

lnx+ln(x+1)=ln12 Find all real-roots

Is "sharpening a pencil" more of a physical change than souring of milk, fermenting of grape juice or rusting of iron? Thanks anyone!

The cola sample is 50. mL, the equivalence point volume is 13.4 mL, and the NaOH solution concentration is 0.025 M, what mass of H3PO4 was in the sample?

Near which type of physical feature was most of the earliest farming villages built?

A student sees a flowerpot pass his 2m high window on the fourth floor in 0.093 seconds. The distance between floors is 4.0m. From which floor did the pot fall?

If 100.0 J are added to 20.0 grams of water at 30.0 degrees Celsius. What will be the final temperature?

Express 55 minutes as a fraction on 1 1/3

express 55 minutes as a fraction of 1 1/3 hours

Of the two fractions 15/21 and 19/17 which is smaller?

A person’s blood glucose level and diabetesare closely related. Let x be a random variable measured in milligrams of glucose per deciliter (1/10 of a liter) of blood. After a 12-hour fast, the random variable x will have a distribution that is approximate...

Samuel drew a blue marble out of a bag in 8 out of 12 pulls. Predict how many times he will draw blue in 30 pulls. Please explain.....

Silver ion reacts with excess CN- to form a colorless complex ion,Ag(CN)2 , which has a formation constant Kf = 3.0*10^20 . Calculate the concentration of [Ag] in a solution prepared by mixing equal volumes of 1.8×10−3m NaNO3 and 0.20M NaCN. When I did th...

i have to write a DBQ on the different views within France of the Vichy government from 1940 to 1944. I wrote the introductory paragraph, with the last sentence as my thesis. Does it look all right? Germany defeated French troops in May 1940 and drove its...

2/9x -1 = 1 How do I find the value of x

Global Telephone charges 30 dollars for monthly phone service, plus a long distance calling rate of 15 cents per minute. After an hour of long distance calling charges,the rate drops to just 5 cents per minute for additional long distance calls. What will...

In 2000, the internatonal price of gold was $270 per ounce, and the price of silver was $5 per ounce. How much silver could be mixed with 9 oz of gold to obtain a mixture that costs $164 per ounce?

Mom served apple pie. John ate 1/2 of the pie. Thomas ate 1/4 of the pie. How much of the pie was eaten? How Much of the pie is left?

how do i calculate the [OH-] and [Ca2+] using the equivalence point? Then I have to calculate the Ksp for calcium hydroxide.

Find the critical numbers of the function. (Enter your answers as a comma-separated list. If an answer does not exist, enter DNE.) h(p) = (p − 2)/(p^2 + 9)

I have an acceleration function and a velocity function that I know the equations for. How would I use those to find the equation for a position function x(t) if x(0) = 0? I'm just looking for a general method, but I can give the equations if needed.

The initial amount is 1 million. Divide it by 4. Divide the result by 5. Divide the result by 2. Divide the result by 20. Subtract 50. Divide by 3 then by 8. Subtract 1. Divide the result by 7. Add 2. Divide by 3. Add 2. Lastly, divide by 5. What result d...

Solve the equation symbolically x+7/8=x+8/9

I'm trying to find the second derivative of h(x)= x^2 + cos(kx) My answer for h'(x) is 2x - ksin(kx) but I'm not sure if that's right. Then the answer I got for h''(x) was h''(x) = 2 - k^2cos(kx) but I'm pretty sure that's wrong based on the graph I was g...

I have the differential equation dP/dt = 0.5(800-P) and I need to get the population equation P(t). Can someone walk me through the steps? Thanks!

How would you prepare 500.0 of an aqueous solution of glycerol with a vapor pressure of 24.8mm Hg at 26 degree Celsius (vapor pressure of pure water=25.21mm Hg)? assume the density of the solution to be 1.00 g/mL.

Bonnie and Clyde are sliding 500 bank safe across the floor to their getaway car. The safe slides with a constant speed if Clyde pushes from behind with 385 of force while Bonnie pulls forward on a rope with 300 of force.What is the safe's coefficient of...

the difference between 3 times a number and 11 is 10

Hello, I have some practice math I'm working through and I'm unsure about the answer. I will also put what I got. Thanks for the help. 1. Solve using any method and identify the system as consistent, inconsistent, or dependent. -2x+y=8 2x+2y=-8 A.) (-4,0)...

Hello, This is the last of questions I have for my practice assignment. Again I will put what I got. Thanks for your help. 1.) Solve the system using substitution. Write answer as an ordered pair. 4x+2y=8 -5x-2=y A.) First equation (-2,8) B.) Second equat...

I have a few questions I need help with! Please explain if my answer was not right how you got to it. I got 1.) B 2.) A 3.) C 1. Solve the system by triangularizing the augmented matrix and using back substitution. If the system is linearly dependent, giv...

I need help with these! I got B for 1. C for 2. and D for 3. Thanks for the help! 1.) Find the values of a, b, and c that will make the statement true. [5 a -2] [5 102] [3 4 –b] = [-3 -4 3] [2c 5 9] [-2 5 9] a.) 8R1-R2--> =R2 b.) -8R1-R2 -> =R2 c.) –8R1 +...

I need some help as I'm totally lost! I need to find the first five terms of each recursive sequence. The n-1 on the problem shows it below the a. 1. A1=3 An=2a n-1- 3 2. C1=64, C2=32 Cn= Cn-2 - Cn-1/2

I need some help. A biologist finds that the population of a certian type of bacteria double seach half-hour. An initial culture has 60 bacteria. 1. What is the population after 3 hours? 2. How long will it take for the number of bacteria to reach 983,040...

In I Am Nujood, what enables Shada to take up Nujood’s cause so quickly and effectively? How does Shada, whom Nujood calls her “second mother,” open up Nujood’s world? Who else teaches Nujood about what a “real” family can be like?

In I Am Nujood, The urban elites Nujood encounters in the courtroom and at the Yemen Times lead very different lives from those of Nujood and the country people of Yemen. How are these “enlightened” people actually disconnected from the rest of their soci...

I need some help! Determine whether infinite geometric series has a finite sum. If so, find the limiting value. 112+56+28+....

1.)The silica that makes up the stationary phase in TLC chromatophraphy is more polar than the mobile phase. What then might the relative positions of the analgesics on the developed TLC plate tell you about the polarity of these molecules? Does this matc...

evaluate without using a calculator [log(5)4 x log(2)10 ]/ [log(25)√10]

express y=0.1(1000)^x in the form lg y =mx+c ,where m and c are constants ,and x is a function of x . Determine the constants m and c and the function x .

Q1: If K=In a -In b +In c -t/bc,show that K=(ac/b)e^(-t/bc). Q2:Express log(8)5 in terms of m ,where m=lg 2 Q3:Given that log (4)3 =a and log(4)5 =b ,express log(75)16 in terms of a and/or b . really don't know how to do these qns..please help ! thanks a...

What mass in kg of NH3 must be used to produce 4.4 multiplied by 106 kg HNO3 by the Ostwald process, assuming 100% yield in each reaction?

Consider the following unbalanced reaction. P4(s) + F2(g) PF3(g) How many grams of F2 are needed to produce 212 g of PF3 if the reaction has a 79.8% yield?

Consider the following unbalanced reaction. P4(s) + F2(g) PF3(g) How many grams of F2 are needed to produce 212 g of PF3 if the reaction has a 79.8% yield? I did 212/.798=265.66 grams do I convert that to moles next?

Commercial brass, an alloy of Zn and Cu, reacts with hydrochloric acid as follows. Zn(s) + 2 HCl(aq) ZnCl2(aq) + H2(g) (Cu does not react with HCl.) When 0.5093 g of a certain brass alloy is reacted with excess HCl, 0.0953 g ZnCl2 is eventually isolated....

BaO2(s) + 2 HCl(aq) H2O2(aq) + BaCl2(aq) What amount of hydrogen peroxide should result when 1.00 g of barium peroxide is treated with 15 mL of hydrochloric acid solution containing 0.0330 g of HCl per mL? So confused... >.<

How man moles of sodium phosphate are there in 0.4 liters of 0.1M Na2HPO4 (MW=141.96 g/mol)? 2.) How many millimoles in 200 ml?

Casper bought some pencils at $.50 each. He had $3 left after the purchase. If he wanted to buy the same number of note pads at $.80 each, he would be short $1.50. Write a linear equation for the number of pencils he purchased. Then solve it.

(cos πx + sin πy)4 = 54; Implicit Differentation

A rocket fired straight up is tracked by an observer on the ground a mile away. a)Show that when the angle of elevation is theta, the height of the rocket in feet is h=5280tan(theta).

Solve it step by step so I can't do the rest. lim x->-infinity (ax^2+b)/(cx+d) Thank you! Answer th

Justin is 10 years less than half his father's age. If Justin is 12 years old, how old is his father?

is 100 over 1000 10%?

How many grams of glycolic acid are needed to react with 30 mL of 0.1 M NaOH?

Multiply. Write each product in simplest form. 1. 2 3/8 * 1 3/5 = 3 4/5 2. 1 5/6 * 2/3 = 11/10 3. 7/8 * 3 1/3 = 35/27 Do I have the correct answers? If not can someone show how to solve them?

3 3/5 * 5/6 = 90/45 Do I have correct answer?

This isosceles triangle has two sides of equal length, a, that are longer than the length of the base, b. The perimeter of the triangle is 15.7 centimeters. The equation 2a + b = 15.7 can be used to find the side lengths. If one of the longer sides is 6.3...

Hydrolysis of a compound A, C7H6cl2 was carried out by refluxing with excess potassium hydroxide solution. the resulting solution was acidified with dilute HNO3 acid and excess silver nitrate was added to precipitate the chloride ions as silver chloride....

How many packs of DVDs can you buy with 198 dollars if one pack costs 18 dollars

1.Using Nerst, find the E of the cell for the dicromate redox system: A.under standard conditions. B.under neutral solutions instead of acid solutions. 2.Use Nerst and the hydrogen half equation to obtain an expression for pH.

A student fires a rocket at 24 degrees above the horizontal. The 10kg rocket comes out of the gun barrel at 1000 m/s, and accelerates 15 m/s^2 uniformly until it burns out 2 seconds later. It then is acted apon by gravity until it hits the ground. I need...

Ken planted 8 flowers and 4 shrubs in his mother's garden. He ran out of fertilizer before he planted 2 of the flowers and 1 of the shrubs, so he planted them without fertilizer. What percentage of plants were planted without fertilizer? A. 12.5% B.25% C....

A helicopter flies south at 185km/hr relative to the ground. The wind is blowing 60km/hr to the west compared to the ground. What is the helicopter's speed to an observer on the ground?

Find the indefinite integral. ∫xe^-4xdx

Name three properties of metal for which metallic bonds are responsible

Oil and water don't mix. We say that oil is

Calculate the concentration of all species in a 0.145M solution of H2CO3

Stereo Inc. sells a stereo system for $300 down and monthly payments of $40 for the next 2 years. If the interest rate is 3.25% per month, find: a) The cost of the stereo. b) The total amount of interest paid. I am having trouble figuring out the correct...

Hi! I am having some trouble with this question, can you please help me? Which of the following describe chemical properties? Check all that apply. - Iodine (a purple solid) becomes a purple gas. - Titanium is less dense that iron . - Water freezes at 0'C...

Can you check to see if I'm correct? Which of these substances are elements? a. silicone b. quartz c. iodine d. water e. silicon f. lead is the answer: c, e, and f?

A bus travels 400 Miles in 8 hours how many miles will the bus travel in 2 days

What mass of water is produced from 10g of sulfuric acid ?

(3-4yi)(6+7i)-[(2-3yi)-3(1+7i)] Express it in a+bi form I got 19+42i-21yi+28y but I do not know how to express it in a+bi form, can you please help me with it?

A computer is purchased at 2000$. After each year, the resale value decreases by 25%. What will the resale value be after 3 years?

In a friendly neighborhood squirt gun contest a participant runs at 7.8 m/s horizontally off the back deck and fires her squirt gun in the plane of her motion but 45' above horizontal. The gun can shoot water at 11 m/s relative to the barrel, and she fire...

The only way to get to Ship Island is to take a boat, which is free for 2 and under, $17 for children 3 to 10 years old, $25 for seniors 62 and over and $25 for everyone else. Debbie paid $116 for 6 people in her family to go to the island for the day. Is...

Elastic behavior: when loads are small how much deformation occurs? What materials deform least?

Suppose that f(x)=x^[1/3](x+3)^[2/3] (A) Find all critical values of f. If there are no critical values, enter None . If there are more than one, enter them separated by commas. Critical value(s) = (B) Use interval notation to indicate where f(x) is incre...

Suppose that f(x)=x−7x^[1/7] (A) Find all critical values of f. (B) Use interval notation to indicate where f(x) is increasing and also decreasing. (C) Find the x-coordinates of all local maxima and local minima of f. (D) Use interval notation to indicate...

Describe the civil war in Syria and Yemen. How are they similar? How are they different?

The population of algae cells in a sample is growing exponentially by 9% each hour. The initial population is 8000. Use the equation below to find the number of algae cells after 15 h.

Answers

The following answers were posted by visitors named Kris.

THANK YOU!! I totally forgot Alaska and Hawaii!

Thank you so much!

1 - find the dist. from the vertical base of the mountain to the cathedral and bridge via trig ratios (tan). remember that the angle of depression = looking horizontally ahead and taking the angle between your gaze and the target. 2 - use pythagoras to fi...

How did you do on this assignment. Did you get these right, because I am confused about the part where it asks you to plug in P=R-C. Where R=-x^2+62 and C=6x+300. However, you only put P=(-x^2+62)+300. What happened to the 6x in C?

Answer to 7 is E, J The pattern is the number they are difference between it's numerical link to the alphabet 15, 20, 20,6, 6,19, 19, 5 (numerical equivilent to letter) 5,0,14,0,13,0,14 (0,5) (difference between each set of numbers) giving you the numbers...

i got the equations from my sister a+d= 2b b= c-2 d=2a but what do i do next?

Thank you The skin plays a major role in A. retention of oxygen and excretion of carbon dioxide. B. absorption of vitamin A and certain drugs. C. synthesis and storage of proteins. D. temperature regulation and sensation. I think the answer is d because t...

Which sentence is Vague pronouns? 25a. Air pollution normally increases along with population growth. This increasing pollution is a big problem for many cities. 25b. Air pollution normally increases along with population growth. This is a big problem for...

2. 6x + 18 =0 6x/6 = 18/6 x = 3??

I'm not so sure that anyone knows the month and day... Historians debate this all the time.

Let x be the amount invested at 10% and y be the amount invested at 12%. We can summarize all of the given information in a table: We can write one equation about the amounts invested and another about the interest from the investments: x + y = 20,000 Tot...

dy/dx=3/2(3x-1)61/2

dy/dx=3/2(3x-1)^1/2 My bad.... apparently didn't hit the shift key for the ^ sign...

Thanks, Dr. Bob. So are new substances formed in a chemical reaction?

This question is a pre-lab assignment, therefore we have not done the titrations yet.

thank you for the the set up of the problem

yes we have a list - it ranges from 2.2 to 12.0 Indicator benzopurpurine (BP) violet 2.2 – 4.2 red bromocresol green (BG) yellow 3.8 – 5.4 blue methyl red (MR) red 4.8 – 6.0 yellow bromothymol blue (BB) yellow 6.0 – 7.6 blue thymol blue (TB) yellow 8.0 –...

Do you think you could be more specific?

Im sorry express 55 minutes as a fraction of 1 1/3

Further notes: *Found r by taking diameter and dividing by two *F = force = 13 N, listed in the problem *A = area, which was found above (to convert from mm to m, multiply the mm figure by 10^-3; to convert from mm^2 to m^2, multiply the mm^2 figure by 10...

*First, calculate the area: Area = (pi)r^2 = (π)4.5^2 = 63.6173 mm^2 = 0.0000636173 m^2 *Now, use this equation to find E, the elastic modulus: E = (F/A) ÷ (ΔL/L0) *Convert all length measurements to m and then plug and chug: E = (13/0.0000636173) ÷ (0.00...

Oh, and the equation for Young's modulus (the elastic modulus), E = (F/A) ÷ (ΔL/L0), is actually stress divided by strain: Stress = F/A Strain = ΔL/L0

Thank you so much!

Do your own work. Acutally read the assignments and you'll do fine.

The law of cosines is: a^2 = b^2 + c^2 - 2cosA or b^2 = a^2 + c^2 - 2cosB or c^2 = a^2 + b^2 - 2cosC the lower case letters are sides, the capital letters are for angles. For this problem, you would do c^2 = 12^2 + 15^2 - 2cos60 That gives you side c. Aft...

Go to the college board website. Then go to the purple box that says student, and click on that. this willl bring up a new page. Under the box that says college board tests (near the top), click on AP. This will bring you to a new page. Go over to courses...

Is that supposed to be (4, -ƒÎ/6)? If so, you would use this formula: x = rcosӨ y = rsinӨ x = 4cos(-ƒÎ/6) y = 4sin(-ƒÎ/6) -ƒÎ/6 on the unit circle is the same as 11ƒÎ/6. The cosine (or x-value) for this angle is ã3/2, and the sine (or y-value) for this a...

You asked this question again under the name Alex, and I answered it. I suggest you look at that answer. :P

No it is inverse

Mn (H2O)63+ (aq) +H2O (l) <--------------> Mn(OH)(H2O)52+ (aq) +H3O+(aq)

Yes, there is a titration curve that goes with this problem.

Well the equivalence point in volume is 11.3 mL and the pH is 7.45. We did a titration lab of calcium hydroxide. Ksp of calcium hydroxide

Kw would be 1.0x10^-15 right? Cant quite remember the exponent

I don't understand this part (pH + pOH = pKw = 14) PKw is equal to 14?

Actually forget that. When you say 1/2 the moles of HCl, do you mean take half of the moles of HCl used originally? Times the volume of equivalence point?

I tried doing it and got 1.96x10^-13...I dunno if it's correct

I keep on coming up with 2 + and - squareroot(2)all over 2. Please help.

Milli means 1,000. Centi means 100. There are 1,000 millimeters in a meter, and there are 100 centimeters in a meter. So to go from mm to m, you need to divide .0023 by 1000. Your answer would then be 2.3*10^-6 I don't know where that 2.3*10^5 came from,...

Actually if you divide .0023 by 10 you get 2.3*10^-4. Then if you divide that by 100 you get 2.3*10^-6. Dividing .0023 by anything would give you a smaller number, and 2.3*10^5 is a very big number. (230,000) 10mm = 1cm 100cm = 1 m 1m = 1,000mm 1m = 1,000...

Here is a paragraph from the Sparknotes page about solutions. A solution is a homogenous mixture of two or more substances that exist in a single phase. There are two main parts to any solution. The solute is the component of a solution that is dissolved...

Oh, okay. I get it now. Thanks!

Oh nevermind, something was just set weird on my calculator that was throwing the graph off. I reset it and it looked like it was supposed to.

I'm assuming you are trying to solve for x? Okay, your first step is to get all of the variables on one side. So subtract 63x from both sides and you get 30x^3+3x^2-63x = 0 The next thing would be to look at what you can "pull out" of all three "sets" of...

I got 4+-sqr(336) / 10 is this right??

I understand but I thought maybe someone could explain it.

John sister has $4.95 in dimes and quarters in her piggy bank. There are 3 fewer dimes than quarters. How many quarters and dimes are in the piggy bank?

Instead of having an "x" for multiplying, the "*" represents multiplication as well. So 93 times 18. The answer would then be 1,674. Hope I helped!

Can you explain why it is yes... Pls.,

i got 88 mol. is that right?

265.66g x (1mol/88) = 3.01 mol PF3 correct?

the balanced equation is P4+6F2-->4PF3 so i have: 3.01mol PF3 x (6 molF2/4molPF3)=4.5mol2F2 So then i convert it to grams, correct?

so is the answer 171 g F2? I did: 4.5 mol F2 x (38 g/1mol) =171g

Thank you very much!

I found the mass of ZnCl2 to be 136.29g I started out: .0953/136.3= 6.9e-4 then I did: 6.9e-4 x 65.39= .046 and multiplied that by a hundred

i understand where my mistake was. when i went to find the %Cu i did: 100%-8.98%= 91.02 (rounding to three sig figs would give me 91.0) both those answers were wrong on the on the online grader

Okay, it needed four sig figs. the next part of the question is: How could this result be checked without changing the above procedure? What does this mean?

Thank you so much!

(cos πx + sin πy)4 = 54

8(d) I tried everything... I can't get any value for 0<=thetha<=pi

8(d) the answer should be thetha = -2*B*t phi = pi/2 I tried thetha = -2*B*t, 2*pi-2*B*t (although this mayn't be always between 0 and pi), 2*B*t (i know its wrong but i tried)

Yes, I was trying to say it should be the answer, but the question required 0<=thetha<=pi... this doesn't satisfy for any answers mentioned above by me... I feel this question is tricky... can someone find the answer?

I bet "Cheaters" don't have answer to this question...

I think that what they mean is to lay out something to count the number, they give you the number 5, find something (beans, legos, something) to act as a counter. Use those counters to count to the number 5, or the number 3, use more counters to count abo...

Sally has a total of 100 coins after she plays a game .she plays 10times how many coins does she have

T=Mg[(v^2/rg)-1] or T=[(3.32107773×10^-27)*g][(((299792458)*8.4)^2)/(g*0.551 m))-1]

Yes C is my answer. I'm I correct.

I know this isn't an answer but i was wondering if you ever found what the answer was?

Thank you so much for this. And I really like the way you lay out the way it is solved. easy to understand.

RICHMOND- you are sir should stop trying to show people how to do physics when you are completely wrong.

America is right I got a 100% with connections academy lesson 8 unit 6

Thank you very much Damon.

Thanks ur mom!!! Got all of them right

Suppose that f(x)=x^[1/3](x+3)^[2/3] (A) Find all critical values of f. If there are no critical values, enter None . If there are more than one, enter them separated by commas. Critical value(s) = (B) Use interval notation to indicate where f(x) is incre...

I dont understand what "Reiny" means by c(2,8) what is c and why is it in an (x,y) form????

Thanks so much Kayla jay!! You saved me from getting a 50% 😂

The answer is A

Don't vote trump.

Sasuke is right. 100%, thanks :)

Friendly is 100% correct!!! Thanks

1. A 2. B 3. B 4. A -2020