题目内容：

We’re surrounded by chemistry in everyday life. Sometimes it is easy to see, like when your science teacher does a big experiment in class. At other times, it can be pretty 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 known 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(醋), because it can produce poisonous gas.Without chemistry, we wouldn’t have fireworks displays on important days.

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 food. Baking is a great example of chemistry. Too much or too little of any ingredient（成分，尤指烹饪） 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 meet hundreds of times every day. Knowing how chemistry works will give you a greater understanding of the science behind some of the simplest-looking 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．How a science teacher 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 get the oil out of 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 mak-ing.

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

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

5.Which of the following would be the best title for the text?

A．Chemistry Around the House

B．Chemistry in Science

C．Chemistry for Dinner

D．Chemistry in everyday life