问题 选择题

将一块铁熔化成铁水,它的(  )

A.体积不变

B.质量不变

C.密度不变

D.质量和体积都不变

答案

质量是物体中所含物质的多少.自然界中的一切物体,大到宇宙中的天体,小到分子、原子,它们都有质量;物体质量的大小与物体的形状、位置、状态的变化无关,只取决于物体本身所含物质的多少.

故选B.

单项选择题
阅读理解

任务型阅读。

     根据短文内容,从短文后的七个选项中选出能填入空白处的最佳选项,选项中有两

项为多余选项。

     The Internet has opened up a whole new online world for us to meet, chat and go where we've never

been before.

     But just as in face-to-face communication, there are some rules of behavior that should be followed

when online.   1   imagine how you'd feel if you were in the other person's shoes.

      For anything you're about to send, ask yourself, "Would I say this to the person's face?" If the answer

is no, rewrite and reread.   2   If someone in the chat room is rude to you, your instinct ( 本能) is to fire

back in the same manner. But try not to do so.   3    if it was caused by a disagreement with another

member, try to fix the situation by politely discussing it. Remember to respect the beliefs and opinions of

others in the chat room.

         4     offer advice when asked by newcomers, as they may not be sure what to do or how to

communicate. When someone makes a mistake, whether it's a stupid question or an unnecessarily long

answer, be kind about it. If it's a small mistake, you may not need to say anything. Even if you feel

strongly about it, think twice before saying anything. Have good manners yourself doesn't give you license

to correct everyone else.   5   at the same time, if you find you are wrong, be sure to correct yourself and

apologize to those that you have offended.

     It is not polite to ask others personal questions such as age, sex, and marital status. Unless you know

the person very well, and you are both comfortable with sharing personal information, don't ask such

questions. 

A. Everyone was new to the rietwork once

B. If you do decide to tell someone about a mistake,  point it out politely

C. It's natural that there are some people who speak rudely or make mistakes online

D. The basic rule is simple: treat others in the same way you would want to be treated

E. You should either ignore the person, or use your chat software to block their messages

F. When you send short messages to a person online, you must say something beautiful to hear

G. Repeat the process till you feel sure that you'd feel comfortable saying words to a person's face.