题干

A﹣F为初中化学常见的六种物质,且都含有一种相同元素,他们相互间的关系如图所示.

已知A、B、C、D、E是不同类别的物质,C俗称纯碱,F是人体中含量最多的物质(部分反应物、生成物及反应条件已略去).

下列关于A﹣F的说法错误的是(   )

A:B和F均属于氧化物

B:B物质的一种用途是人工降雨

C:C与E正反应会生成一种白色沉淀

D:图中物质相互间发生的反应未涉及的基本反应类型是化合反应

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D

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      Do you feel lonely when your best friend isn't around? Here's our advice to you ---and to all kids who feel lonely sometimes. 
It's hard when a best friend isn't around --- maybe because he or she moved to a different school or a different class. You may feel left out at break or lunchtime. You want to have new friends, but how do you make them? Maybe it seems everybody else already has his or her friends. But remember, there's always room for more friends.
      Start by looking around your classroom --- think about which kids you'd like to play with at break. Look for chances to say hi to them, smile, and be friendly. Offer to share something or express your appreciation (欣赏) to them. Invite someone to play with you or say, “Do you want to sit here?”in the lunchroom. When you're at break, walk over to kids you want to play with, act friendly, and say “Hi, can I play, too?” or just join in. 
     If you have trouble doing this or if you're feeling shy, ask your teacher to help you make new friends. Teachers are usually pretty good at matching up friends. The best way to make friends is to be a friend. Be kind, be friendly, share, say nice things, offer to help ---and pretty soon, you'll have one, or two, or even more new friends.
     You might still miss that special best friend. But when you see each other, you can share something you didn’t have before he or she left. You can introduce him or her to your new friends!
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