题干

用NA表示阿伏加德罗常数的值。下列叙述正确的是(   )

A:常温常压下的33.6L氯气与27g铝充分反应,转移电子数为3NA

B:标准状况下,22.4L己烷中共价键的数目为19NA

C:由CO2和O2组成的混合物中共有NA个分子,则其中的氧原子数为2NA

D:1L浓度为1mol·L-1的Na2CO3溶液中含有NA个CO32-

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C

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     When I was a child, my parents always told ~ne that I should never talk to strangers. This was part of a whole list of things I should never do: Never accept food or candy from strangers, never get in a car with strangers, and so on.

      But if we didn't start a conversation with strangers, we'd never make new friends. We'd never get a job. ①We may miss the joy that comes from talking with strangers. And the more people you know, the more chances you can find.

     The following passage offers you some advice on how to ②break the ice.

     Don't just stare at your shoes. Go and say "Hi" to that new guy. It will be easier to break the ice if you know more about different cultures.

     British : Beautiful day, isn't it?

     The weather in Britain is changeable. So, it's one of the topics the British care most about. And there's a simple rule: Say "Yes" whether you agree with the person's idea on the weather or not. ③That's because the British start a conversation using the weather so that they era, continue their talk.

     French: Where did you. go on holiday?

     To talk with a French person, the safest way is to ask about his or her last holiday. French students enjoy a 10-to-15-day holiday every two months. French employees(雇员) get more than six weeks of holidays per year.

     American: So, where are you from?

     The US is so big and people move so often that location is always a source (来源) of talk. You can try to find a connection with the place they're from. For example, if someone's from Los Angeles, you could say, "Oh, I have a friend who studied there."