题干

下列叙述正确的是①一定温度和压强下,气体体积主要由其分子的大小决定
②一定温度和压强下,气体体积主要由其分子的物质的量决定
③气体摩尔体积是指单位物质的量气体所占的体积,其单位是L
④不同的气体,若体积不相等,则它们所含的分子数一定不相等
⑤在同温同体积时,气体的物质的量越大,则压强越大

A:②⑤

B:①③

C:②③⑤

D:②④⑤

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答案(点此获取答案解析)

A

同类题4

阅读下面四篇短文,从每题所给的A、B、C、D四个选项中选出最佳选项。

B

 

    Think of life as a game in which you are playing with five balls in the air. You name them work, family, health, friends and spirit and you keep all of them in the air. You will soon understand that work is a rubber ball. If you drop it, it will bounce back.  

    But the other four balls, family, health, friends and spirit, are made of glass. If you drop one of these, it will be broken and never be the same. You must understand that and try to have balance in your life. How ?  

    Don't look down on your worth by comparing yourself with others. It is because we are different and each of us is special.  

    Don't let other people set goals for you. Only you know what is best for yourself.  

    Don't give up when you still have something to give. Nothing is really over until the moment you stop trying.

    Don't be afraid of difficulties. It is by taking chances that we learn how to be brave.

    Don't shut love out of your life by saying it's impossible. The quickest way to receive love is to give it; the fastest way to lose love is to hold it too tightly; the best way to keep love is to give it wings.  

    Don't run through life so fast that you forget not only where you've been, but also where you are going.  

    Don't be afraid to learn. Knowledge is weightless. It's a treasure you can always carry easily.  

    Don't use time or words carelessly. You can't get them back. Yesterday is history, tomorrow is a mystery*, and today is a gift; that's why we call it “the present”. Life is not a competition, but a trip, step by step.