题干

小张将一瓶矿泉水在冰箱中放较长时间后取出,一会儿发现瓶外壁出现小水珠。用干毛巾擦净,等一会儿又出现小水珠。于是他与小吴一起对此现象进行研究,但观点不一致。小张认为这是矿泉水瓶内的水往外渗透后,附着在矿泉水瓶外壁上;而小吴则认为是空气中的水蒸气液化成小水珠附着在矿泉水瓶外壁上。请你设计一个实验证明他俩的结论是否正确。

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答案(点此获取答案解析)

1.室温下,取一瓶与研究对象相同的矿泉水,称量质量m1;2.将矿泉水拧紧瓶盖,放入冰箱较长时间,取出放在室内一段时间,待矿泉水完全恢复至室温后,将矿泉水外壁完全擦干,称量质量m2;3.比较m1、m2的大小,如果m1>m2,则小张是正确的;如果m1=m2,则小吴是正确的。

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    English can be a difficult language to learn, but there are certain things you can do to learn the language a lot faster. People can master English as long as they take the time to practice speaking, reading and writing in English. ____

    Start by taking a class that teaches beginning English. These classes are often named as “ESL” classes, or “English as a Second Language.” ____

    Buy an English audio(音频的) course. You can go over these classes in your spare time and learn quite a bit. Buy an audio course and listen to it in the car or while working, if possible. The higher the quality of the course, the quicker you'll learn.

    Practice speaking English with other people, especially with native English speakers. ____And make sure they are willing to help you learn English by having simple conversations with you. You will probably be surprised at how quickly you can start having a conversation in English.

    ____ Pay attention to the dialogue and try to figure out what the actors are saying. Congratulate yourself when you are able to pick out certain words and phrases that you understand.

    Read newspapers, books and magazines that are printed in English. At first they maybe very difficult, but as your knowledge grows so will your understanding of written English. ____ It will help you a lot in learning to speak the language much faster.

A. Try to understand written English.

B. Watch television shows or movies that are in English.

C. Read and remember as many English words as possible.

D. Here we will show you how to learn to speak English quickly.

E. Every morning you should get up very early and read English.

F. Make friends with people speaking English as their native language.

G. The teachers of these classes have the experience to teach the students.