Question

We're surrounded by chemistry in everyday life. Sometimes it is easy to see, like when your science teacher conducts a big experiment in class. At other times, it can be extremely hard to see everyday chemistry at work, but nearly everything you touch or use has some element of chemistry in it.

Something as simple as toothpaste contains at least three chemicals, if not more. It is the mixture of them and its chemical reaction that keeps your teeth clean. Other things you use every day are created by chemistry, such as hair products, shampoo and soap. Adding detergent (洗涤剂) to water involves chemistry. Without chemistry, we would never have realized that we need soap to get the oil out of clothes or skin.

Chemistry not only helps us make products for use, but it also helps us understand the world around us. Chemistry helps us understand what the ozone layer (臭氧层) is and how it protects us. Chemistry also gives us sunscreen to protect us from the sun. Thanks to chemistry, we know bleach (漂白剂) can't be mixed with vinegar, because it can produce poisonous gas. Without chemistry, we wouldn't have had fireworks displays on important days like the Spring Festival.

Chemistry plays a big role in food preparation. Cooking food causes it to go through a chemical change. That is why cooked food often tastes different from raw (生的) food. Baking is a great example of chemistry. Too much or too little of any ingredient makes a difference to the result of baking, for example, the dough (面团) won't rise or the cake will be flat.

Chemistry isn't something that just lives in a lab; it's something that you come across hundreds of times every day. If you know how chemistry works, you will get a greater comprehension of the science behind some of the simplest­looking things.

1.What's the main idea of Paragraph 1?

A. Chemistry is easy to see around us.

B. Sometimes chemistry is hard to see around us.

C. A science teacher often does a big experiment.

D. Few things in everyday life contain chemistry.

2.The following actions are about chemistry EXCEPT ________.

A. cleaning teeth with toothpaste    B. washing hair with hair products

C. using soap to remove the oil from clothes    D. washing your face with water

3.The underlined word “poisonous” in Paragraph 3 means ________.

A. harmful    B. healthy    C. fresh    D. pleasant

4.Which one is TRUE according to Paragraph 4?

A. One can't find chemistry when cooking food.

B. Chemistry plays an important part in food making.

C. That dough rises is nothing to do with chemistry.

D. A flat cake is the result of too many ingredients.

Answer

1. B

2. D

3. A

4. B

【解析】

试题本文叙述了在人们的日常生活中化学无时不在无处不在，文中举了一些例子，来说明化学能够帮助我们理解我们的生活中的一些自然现象，我们的生活离不开化学。

1.概括大意题。根据第一段第一句We're surrounded by chemistry in everyday life. 可知我们日常生活中到处都有化学。所以D错误，再根据下文举的例子，可知在化学课上老师做实验时能见到，但与C描述相反。再根据后一句At other times, it can be extremely hard to see everyday chemistry at work, but nearly everything you touch or use has some element of chemistry in it. At other times, it can be pretty hard to see everyday chemistry at work,可知A错误，有些化学不易看到，故选B。

2.细节理解题。根据Something as simple as toothpaste contains at least three chemicals 和Other things you use every day are created by chemistry, such as hair products, shampoo and soap.水里没有化学物质，故选D。

3.词义猜测题。根据Thanks to chemistry, we know bleach (漂白剂) can’t be mixed with vinegar(醋), because it can produce poisonous gas 两者不能混合，混合在一起会发生反应而产生对身体不利的东西，毒气，故选A。

4.细节理解题。根据Chemistry plays a big role in food preparation，可知，化学在食物制作中起重要作用， 故选B。