问题 选择题

下表除去杂质的方法中,正确的是(  )

选项物质(括号内为杂质)除去杂质的方法
ACu(NO32溶液(AgNO3加过量铜粉,过滤
BKCl溶液(CaCl2加适量Na2CO3溶液,过滤
CFe(Zn)加足量稀盐酸,过滤
DCO(CO2通过灼热的氧化铜粉末

A.A

B.B

C.C

D.D

答案

A、AgNO3能与过量铜粉的发生置换反应生成硝酸铜和银,再过滤除去不溶物,能除去杂质且没有引入新的杂质,符合除杂原则,故选项所采取的方法正确.

B、CaCl2能与适量Na2CO3溶液反应生成碳酸钙沉淀和氯化钠,氯化钾不与Na2CO3溶液反应,能除去杂质但引入了新的杂质氯化钠,不符合除杂原则,故选项所采取的方法错误.

C、锌、铁均能与稀盐酸反应,选用稀盐酸不但能把杂质除去,也会把原物质除去,不符合除杂原则;故选项所采取的方法错误.

D、CO能与灼热的氧化铜粉末反应生成铜和二氧化碳,二氧化碳不能与氧化铜反应,通过灼热的氧化铜粉末反而会把原物质除去,不符合除杂原则,故选项所采取的方法错误.

故选A.

阅读理解

Camping in your backyard is full of fun, whatever your age is. It’s great for keeping us relaxed. It offers chances to enjoy the night sky and to be noisier(更热闹) than usual. It lets us have friends over to stay who might not fit inside the house! Follow these instructions and you’ll have a night you’ll never forget!

Put up your tent

Considering the  (1)  of family members and guests, you may need more than one  (2) . Tell your friends to bring their tents if needed. Follow the instructions or check out the articles on how to put up a tent on the Internet.

Prepare your bedding

You’ll want your guests to be able to relax in comfort. Put something soft to lie on the floor: A blow-up air mattress(床垫) or thick comforters may work well. Fill the tent with soft toys and blankets. Have lightweight sleeping bags or cotton blankets. (3)They are especially important if you live where the night temperatures drop greatly.

Prepare a seating area

If you have a picnic table, that would work best. If not, set up a few chairs and a small table to set out(摆出) drinks and food. A simple choice is to lay out a blanket in the open air, so that your friends can eat and talk. Be sure the grass isn’t wet!

Make memories

Plan some activities. You’re camping in the backyard, so it’s time to make the most of being outdoors.

Have a camera nearby to take photos of you, your family members, and your friends. Take one large group shot with everyone smiling and laughing. Be sure to make copies for everyone!

小题1:在(1)(2)空白处分别填入一个适当的词使句意完整,上下文通顺。

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小题2:回答问题:What can we do to help remember the camping activities?

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小题3:把(3)句译成中文。

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小题4:在文中找出与“Your guests are expected to relax themselves comfortably.”意思相近的句子。

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小题5:在文中找出最能表达该短文主题的句子。

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单项选择题