B. Haq
From gravel to asphalt, roads have come a long way to serve transportation purposes. They have been a part of a long and winding journey humans have embarked on in their quest to make the roads travel friendly.
Looking in the rearview, we see the first paved roads invented by Mesopotamians around 3000 B.C. Thousands of red clay bricks, glued with a natural sticky material called bitumen, were positioned in neat rows. Bitumen is still used today as a binding material in asphalt. Romans used layers of rock and gravel to build long routes throughout the Roman Empire.
During the industrial era, gravel was crushed into tiny pieces and spread out and rolled over with heavy rollers to make the road more durable, especially in the rainy season. In the late 19th century, builders started mixing gravel with bituminous to make an asphalt mixture to use as the topmost layer. They also used concrete as a top layer for paved roads. This practice continues to date.
The quest continues to build roads to last a long time, without the need for repairs. Asphalt cracks and breaks easily creating a hazard for drivers. During the fall and winter, water gets into cracks and freezes, making the cracks bigger and more dangerous. Engineers have been looking into different options to make roads smoother, more shock and noise absorbing, and with longer lifespans.
Denmark is testing a low-friction material that will help drivers maintain a steady speed, thereby reducing fuel usage. Flexi-pave is another material, which is asphalt mixed with recycled tires and plastic, to make a more durable and quieter road. Some countries are already using this material.
Another solution is a self-repairing road, which has steel-wool fibers mixed with asphalt. When cracks start to appear, a truck-mounted with a huge magnet is driven over the road. The steel fibers contract, and the asphalt heats up and closes the gaps. Absorbent concrete is another new material that helps deal with the problem of water drainage. The material is porous and absorbs massive quantities of water during heavy rains or floods.
A unique combination of asphalt and graphene, which is a thin layer of graphite, could significantly extend the life of roads. Solar roads are an energy-saving option but very costly, so they are probably not going to be used anytime soon.
These are some of the new ideas in road-construction. Human creativity knows no bounds, and we will surely see more modern ways to make our trips on the road smoother and safer.
Question
Select two of the sentence options to create an objective summary of paragraph 4.
Responses
A The most common road-building material, asphalt, has proven to be not so reliable.The most common road-building material, asphalt, has proven to be not so reliable.
B The struggle to build durable roads is not new to the engineers, who have always worked hard.The struggle to build durable roads is not new to the engineers, who have always worked hard.
C Uncommon road-building materials are strong enough to construct smooth roads.Uncommon road-building materials are strong enough to construct smooth roads.
D In their efforts to build better roads, engineers have continued to investigate various materials and methods.In their efforts to build better roads, engineers have continued to investigate various materials and methods.
E Bad weather impacts the surface of a road, making it unsafe and unusable.
1 answer
To create an objective summary of paragraph 4, the best sentence options are:
B. The struggle to build durable roads is not new to the engineers, who have always worked hard.
D. In their efforts to build better roads, engineers have continued to investigate various materials and methods.
