Can someone let me know which is the correct answer and why?

Question

Thanks!

Subject-verb agreement A
1a. Did you know a famous animal-rights activist has criticized horseracing because of the dangers involved? 1b. Did you know a famous animal-rights activist have criticized horseracing because of the dangers involved
Subject-verb agreement B
2a. Peer editing academic papers require critical-thinking skills and diplomacy.
2b. Peer editing academic papers requires critical-thinking skills and diplomacy.
Subject-verb agreement A
3a. Vitamins that are sold in a health-food store are not regulated by the Food and Drug Administration.
3b. Vitamins that are sold in a health-food store is not regulated by the Food and Drug Administration.
Using regular and irregular verbs A
4a. John has become a rather good actor.
4b. John has became a rather good actor.
Using regular and irregular verbs A
5a. Some athletes have taken drug tests to prove they are not on steroids.
5b. Some athletes have took drug tests to prove they are not on steroids.
Using regular and irregular verbs B
6a. I lay my book on the table, but now I cannot find it.
6b. I laid my book on the table, but now I cannot find it.
Using the correct form of be and have in the present tense B
7a. I was interested in working on the presidential campaign if the opportunity still exists.
7b. I am interested in working on the presidential campaign if the opportunity still exists.
Verb form and verb tense B
8a. Since American Idol premiered on television, many talented contestants have appeared on the show.
8b. Since American Idol premiered on television, many talented contestants appeared on the show.
Verb form and verb tense A
9a. The ancient Egyptians built pyramids as burial sites for their leaders.
9b. The ancient Egyptians have built pyramids as burial sites for their leaders.
Identifying antecedents A
10a. The antecedent in the following sentence is students: Students in online classes have to be organized to keep up with their assignments.
10b. The antecedent in the following sentence is class: Students in online classes have to be organized to keep up with their assignments.
Identifying antecedents B
11a. The antecedent in the following sentence is Doctors: Doctors should schedule more time for patients so they do not spend so much time in the waiting room.
11b. The antecedent in the following sentence is patients: Doctors should schedule more time for patients so they do not spend so much time in the waiting room.
Pronoun-antecedent agreement B
12a. When a driver wants to buy a new vehicle, he or she usually test drives them. 12b. When a driver wants to buy a new vehicle, he or she usually test drives it.
Pronoun-antecedent agreement B
13a. Most presenters spoke without looking at his or her notes.
13b. Most presenters spoke without looking at their notes.
Pronoun-antecedent agreement B
14a. You may rent a movie or a video game for just one night if they are new.
14b. You may rent a movie or a video game for just one night if it is new.
Pronoun-antecedent agreement with indefinite pronouns A
15a. Neither the mayor nor the council members have filed their reports.
15b. Neither the mayor nor the council members have filed his reports.
Pronoun-antecedent agreement with indefinite pronouns B
16a. Anyone who requests a copy of the game may have it for their video library.
16b. Anyone who requests a copy of the game may have it for his or her video library.
Pronoun-antecedent agreement with indefinite pronouns A
17a. Each of the applicants must submit his or her completed form to the interviewer.
17b. Each of the applicants must submit their completed forms to the interviewer.
Pronoun case A
18a. My brother knows more about technology than me.
18b. My brother knows more about technology than I.
Pronoun case B
19a. Please send an invitation to Bob and she.
19b. Please send an invitation to Bob and her.
Pronoun case A
20a. My best friend and I are going to Hawaii this summer.
20b. My best friend and me are going to Hawaii this summer.
Pronoun case for who and whom A
21a. Who was the star of last year’s award-winning movie?
21b. Whom was the star of last year’s award-winning movie?
Pronoun case for who and whom B
22a. To who should we send the letter of commendation?
22b. To whom should we send the letter of commendation?
Pronoun case for who and whom A
23a. Jon Bon Jovi, who is a well-known singer and actor, also owns an arena football team.
23b. Jon Bon Jovi, whom is a well-known singer and actor, also owns an arena football team.
Vague pronouns A
24a. When the car hit a tree, it made a terrible noise.
24b. The car made a terrible noise as it crashed into a tree.

Answer 1

You did a great job! You only have 3 errors.

Verb form and verb tense B
8a. Since American Idol premiered on television, many talented contestants have appeared on the show.
8b. Since American Idol premiered on television, many talented contestants appeared on the show.
With this construction -- "since . . ." you need the past participle form of the verb. The correct answer is A.

Pronoun case A
18a. My brother knows more about technology than me.
18b. My brother knows more about technology than I.

We use the subjective form of a pronoun after than. This is a short cut for saying, "My brother knows more about technology than I do.

Vague pronouns A
24a. When the car hit a tree, it made a terrible noise.
24b. The car made a terrible noise as it crashed into a tree.
What made the terrible noise? In sentence a, we can't tell because it could have been the tree that made the noise. Sentence b avoids the use of a vague pronoun.

Thanks to Writeacher for supplying us with the answer key for this oft-seen test/exercise. :-)

Answer 2

What makes these two sentences "Vague Pronouns".
1. Air pollution normally increases along with population growth. this increasing pollution is a big problem for many cities.
2. Air pollution normally increases along with population growth. This is a big problem for many cities.

Answer 3

1. - Ask yourself this question. What is a big problem for many cities? Is it air pollution or population growth?
This is why it is vague. You have to ask yourself what is a big prolbem for many cities.

So the correct answer would be the sentence that tells you exactly what the big problem is.