问题 选择题

下列叙述中,前者是化学性质,后者是该项性质表现出来的化学变化的是(  )

A.蜡烛有可燃性-----点燃蜡烛产生黄色火焰,生成了气体

B.铁的熔点高达1535℃----熔化的铁极易在空气变成黑色物质

C.酒精易挥发----滴几滴酒精在手心中感到凉意

D.汽油能燃烧----人靠近汽车闻到一股刺激性油味

答案

A、蜡烛有可燃性需要通过化学变化表现出来,属于蜡烛的化学性质,点燃蜡烛产生黄色火焰,生成水和二氧化碳,属于化学变化.故A正确;

B、铁的熔点高达1535℃,不需要通过化学变化表现出来,属于铁的物理性质,熔化的铁在空气中变成黑色物质,说明铁发生了化学变化.故B错误;

C、酒精易挥发,无需化学变化就可表现出来,而将酒精滴在手心中感到凉意是因为酒精蒸发时吸收热量,没有新物质生成,属于物理变化.故C错误;

D、汽油能燃烧需要通过化学变化表现出来,属于汽油的化学性质,人靠近汽车闻到刺激性气味的过程中没有新物质生成,属于物理变化.故D错误;

故选A.

阅读理解

任务型阅读:阅读下面短文,根据短文内容完成下列句子。 

       English is very interesting and it is widely used nowadays.    

       If your classmate says to you,"I can speak five countries' languages",  don't be surprised.  You can

say, "Oh yes,I can, too.  I can speak the language of Britain, America, Canada, Australia and New

Zealand."   

       From the words, we can see English is so widely used. You can see English everywhere. English is

written on many things. When you open your calculator(计算器),you can see the words-"on","off",

"shift", "mode" and so on.  When you walk in the street, you can see "Kentucky Fried Chicken"、

"DRIVE SLOWLY!" "'Sky Book Shop" beside you.  When we go into the shop, we can see

"CocaCola"、"Rejoice"(飘柔)and "Safeguard"(舒肤佳).    

       Every day, in the school, when we students meet, we say "Hi!" or "How are you?". When

somebocly makes good friends, he will say "Good!". And when a boy fails the exam, he will say

"Bad luck!". Another,a student meets something strange, he will shout "Oh, my god!". And on

theplayground, when a class wins the football game, we will say "Congratulations!".    English is

not only in our book  but in our English class.  We can use it all the time.  Let's try to learn

English well!

1. When your cla.ssmate told you that he could speak five languages, you shouldn't be________.

2.  "Nowadays, you c:an see English everywhere."means English is_______.

3. You can find some English words, such as________on your calculator.

4. When a boy didn't pass the exam, he would say"________"to express his feeling.

5. When our football team beat. another one, we will say"_______"to the team members.

单项选择题