问题 选择题

下列反应属于放热反应的是(  )

①稀硫酸与氢氧化钾溶液反应

②锌与稀硫酸的反应

③生石灰变成熟石灰的反应

④氢氧化钡晶体和氯化铵晶体混合反应

⑤石灰石高温煅烧

⑥灼热的炭与CO2反应

⑦甲烷与O2的燃烧反应

A.①②③⑤

B.①②③⑦

C.①②⑤⑥⑦

D.④⑥

答案

答案:B

稀硫酸与KOH发生中和反应是放热反应,①对;锌与稀硫酸的反应为放热反应,②对;CaO与水反应生成Ca(OH)2的反应为放热反应,③对;氢氧化钡晶体与氯化铵晶体的反应为吸热反应,④错;CaCO3高温分解反应为吸热反应,⑤错;灼热的炭与CO2的反应为吸热反应,⑥错;甲烷的燃烧反应为放热反应,⑦对,所以B对。

阅读理解

阅读理解。

      Fangfang, a 15-year-old Chinese girl, likes eating snacks very much. She prefers cream biscuits,

McDonald's food, KFC, and Beijing roast duck. Sometimes she eats two packages of biscuits a day. As a result,

she becomes overweight

      Today in China, there are many children like Fangfang. They like snacks. They don't eat enough healthy

foods like vegetables and fruit. It's very bad for their health. Poor eating habits are a serious problem.

      Health experts say that children should have healthy eating habits. First, they must eat regular meals and

begin with a good breakfast. Second, they should have different kinds of foods, such as fruit, vegetables, grain,

eggs, milk and meat and so on. Third, the children shouldn't eat too many snacks and fried foods. They are

delicious, but eating too much of them is unhealthy.

      If children do as the experts say, they won't become fat. They will be healthier. Students won't become

tired at school, and they will have enough energy to study well.

1. What does the underlined word "overweight" mean? [ ]

A. 聪明的

B. 懒惰的

C. 超重的

D. 痴呆的

2. Fangfang becomes overweight, because _____. [ ]

A. she is an American girl

B. she has a balanced diet

C. she likes eating snacks

D. she likes vegetables soup

3. What kind of food is good for your health? [ ]

A. Fast food.

B. Snacks.

C. Fried food.

D. Vegetables and fruit.

4. If students do as the experts say, they will ______. [ ]

A. become fatter and fatter

B. become more and more beautiful

C. have enough energy to study

D. be healthier and more tired

5. Which of the following is True? [ ]

A. Eating snacks is good for your health.

B. Fangfang doesn't like Beijng roast duck.

C. Fangfang comes from America.

D. Students shouldn't eat too much fried food.

单项选择题