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B1 READING PART3 EXERCISE4

B1 READING PART3 EXERCISE4

Instructions:

You are given a piece of text with some questions.

You are also given a set 4 choices for each question.

Identify the correct answer and click its corresponding button.

 

Once all the questions have been answered, click on the check button.

Correct answers will appear in green, incorrect answers in red.

Your mark will be given as a percentage.

1 / 5

Graphene

If you look at our planet from space, it looks blue because there is so much water on it. There is, however a very big problem. Although 70% of the Earth is covered in water, a very small amount of it is available for people to drink, because most of it is seawater, which contains salt, and humans and animals can’t drink water with salt in it. At the moment, over 780 million people around the world do not have easy access to clean water. The problems are only expected to get worse, with climate change and the fact that the world population is increasing.

A scientist, Rahul Nair, has been working on a clever solution for the past few years. He has been studying new methods of getting the salt out of the water using something new, called graphene. This wonder material is a single layer of tightly packed carbon atoms, which is harder than a diamond, 200 times stronger than steel, one million times thinner than a piece of human hair, and extremely flexible. It can be used for many things from medicine to energy, electronics, and even removing salt from seawater.

The material proved to be excellent at taking out all the small things that float around, and most of the salt from the water. However, there was a problem when it was used with water. When used in this way, the water caused it to swell and widens its holes, and so it became possible for some of the smallest pieces of salt to get through, and the water was no longer drinkable.

Now, the research team thinks it has managed to control the problem. They have found a clever way to limit the swelling by covering the material with a special resin. This only allows fresh, drinkable water to get through the tiny holes. The scientists believe that the ability to carefully control the hole size will open up opportunities for this material to be used in other ways. If they are right, the world’s drinking-water problem could be solved and that is very good news for many people.

Questions

1) The problem of not having enough drinking water

2 / 5

2) Graphene is valuable

3 / 5

3) What problem does graphene have?

4 / 5

4) The scientists feel that graphene’s problems with water

5 / 5

5) What would be a good introduction to this article?

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