问题 选择题

下列物态变化中,属于熔化的是(  )

A.铁块化成铁水

B.盘子里的水晾干了

C.湖水表面结冰

D.水沸腾时水面出现“白气”

答案

A、固态的铁块化成液态的铁水,是熔化过程.符合题意.

B、盘子里的水是液态,水晾干了,是水变成了水蒸气.液态变为气态的过程是汽化.不符合题意.

C、湖水是液态的,冰是固态的,水结冰是由液态变为固态,是凝固.不符合题意.

D、水沸腾是,水变为水蒸气,是汽化,上升的水蒸气遇冷又液化成小水滴.不符合题意.

故选A.

单项选择题 A1/A2型题
阅读理解

This year 2,300 teenagers ( young people aged from 13-19 ) from all over the world will spend about ten months in U.S. homes. They will attend U.S. schools, meet U.S. teenagers, and form impressions (印象) of the real American teenagers. American teenagers will go to other countries to learn new languages and have a new understanding of the rest of the world.

Here is a two-way student exchange in action. Fred, nineteen, spent last year in Germany with George's family. In return, George's son, Mike, spent a year in Fred's home in America.

Fred, a lively young man, knew little German when he arrived, but after two months study, the language began to come to him. School was completely different from what he had expected — much harder. Students rose respectfully (尊敬地) when the teacher entered the room. They took fourteen subjects instead of the six that are usual in the United States. There were almost no outside activities.

Family life, too, was different. The family's word was law, and all activities were around the family rather than one of the members. Fred found the food too simple at first. Also, he missed having a car.

“Back home, you pick up some friends in a car and go out and have a good time. In Germany, you walk, but you soon learn to like it.”

At the same time, in America, Mike, a friendly German boy, was also forming his idea. “I suppose I should criticize (批评) American schools.” he says. “It is far too easy by our level. But I have to say that I like it very much. In Germany we do nothing but study. Here we take part in many outside activities. I think that maybe your schools are better in training for citizens. There ought to be some middle ground between the two.”

小题1:The whole exchange program is mainly to ____.

A.help teenagers in other countries know the real America

B.send students in America to travel in Germany

C.let students learn something about other countries

D.have teenagers learn new languages小题2:What did Fred and Mike agree on?

A.American food tasted better than German food.

B.German schools were harder than American schools.

C.Americans and Germans were both friendly.

D.There were more cars on the streets in America.小题3: What is particular (特别的) in American schools?

A.There is some middle ground between the two teaching buildings.

B.There are a lot of after-school activities.

C.Students usually take 14 subjects in all.

D.Students go outside to enjoy themselves in a car.小题4:What did Mike think after experiencing the American school life?

A.A better education should include something good from both America and Germany.

B.German schools trained students to be better citizens.

C.American schools were not as good as German schools.

D.The easy life in the American school was more helpful to students.