问题 选择题

如图所示的四种现象中,其物态变化过程要放热的是(  )

A.

开空调房间的窗户玻璃上有水滴

B.

用干手器将手烘干

C.

春天冰雪消融

D.

冰冻的衣服晾干

答案

A、玻璃上的水滴是水蒸气液化形成的,液化过程中放热;故A正确;

B、手上的水被吹干,是水发生了汽化现象,汽化过程中吸热;故B错误;

C、冰雪逐渐消融,是熔化现象,此过程吸热;故C错误;

D、结冰的衣服会变干,是由于衣服上的冰发生升华现象,升华过程中吸热;故D错误;

故选A.

阅读理解

阅读理解。

Paragraph 1

     Scientists have learned a lot about the kinds of food people need. They say that there are several kinds of

food that people should eat every day. They are: (1) green and yellow vegetables of all kinds; (2) citrus (柑橘)

fruits and tomatoes; (3) potatoes and other fruits and vegetables; (4) meat of all kinds,fish and eggs; (5) milk

and food made from milk; (6) bread or cereal (谷类), rice is also in this kind of food; (7) butter, or something

like butter.

Paragraph 2

     People in different countries and different places of the world eat different kinds of things. Foods are

cooked and eaten in many different kinds of ways. People in different countries eat at different times of the

day. In some places people eat once or twice a day; in other countries people eat three or four times a day.

Scientists say that none of the differences is really important. It doesn't matter whether foods are eaten raw

(生的) or cooked, canned or frozen. It doesn't matter if a person eats dinner at four o'clock in the afternoon

or at 11 o'clock at night. The important thing is what you eat every day.

Paragraph 3

     There are two problems, then, in feeding the large number of people on the earth. The first is to find some

ways to feed the world's population so that no one is hungry. The second is to make sure that people

everywhere have the right kinds of food to make them grow to be strong and healthy.

1. According to the scientists, which of the following groups of food is the healthiest for your lunch? [ ]

A. chicken, apples, cereal, cabbages

B. potatoes, carrots, rice, bread

C. oranges, bananas, fish, tomatoes

D. beef, pork, fish, milk

2. It is important for people to _____. [ ]

A. eat three times a day

B. have dinner at twelve o'clock

C. eat cooked food all the day

D. eat something from each of the seven kinds of food every day

3. People in different countries and different places of the world _____. [ ]

A. have the right kinds of food to cat

B. cook their food in the same way

C. have their meals at the same time

D. eat food in different ways

4. Which of the following is not true? [ ]

A. People in some places don't have enough to eat.

B. There are too many people in the world.

C. One of the problems is that no one is hungry.

D. The scientists are trying to make people grow to be strong and healthy.

5. If there is Paragraph 4,what do you think is going to be talked about?  [ ]

A. When people eat their lunch.

B. What to do with the two problems.

C. How to cook food in different ways.

D. Why people eat different kinds of food.

多项选择题