下列实验能够成功的是( ) A.用新制Cu(OH)2(必要时加热)可鉴别CH2O

题型:选择题

问题:

下列实验能够成功的是(  )

A.用新制Cu(OH)2(必要时加热)可鉴别CH2O、HCOOH、CH3OH三物质的溶液

B.将乙醇加热到170℃可制得乙烯

C.用乙醇、冰醋酸及pH=0的H2SO4加热可制乙酸乙酯

D.用饱和的Na2CO3溶液除去CO2中的HCl

考点:实验操作达到的预期目的
题型:选择题

违反《消防法》的规定,公安消防机构应当责令当场改正的行为是()。

A.擅自举办大型集会具有火灾危险的

B.对火灾隐患不及时消除的

C.阻拦报火警或者谎报火警的

D.不能保障疏散通道畅通的

题型:选择题

根据医院病床编设的原则,三级综合医院病床编设不宜超过()

A.200张

B.500张

C.700张

D.800张

E.1000张

题型:选择题

植物的光合作用会消耗空气中的[ ]

A.氧气

B.二氧化碳

C.氮气

D.稀有气体

题型:选择题

Children start out as natural scientists, eager to look into the world around them. Helping them enjoy science can be easy; there is no need for a lot of scientific terms or expensive lab equipment. You only have to share your children’s curiosity. Firstly, listen to their questions. I once visited a classroom of seven –year- olds to talk about science as a job. The children asked me “textbook questions” about schooling, salary and whether I liked my job. When I finished answering, we sat facing one another in science. Finally I said,” Now that we’ve finished with your lists, do you have questions of your own about science?”

After a long pause, a boy raised his hand, “have you ever seen a grasshopper eat? When I try eating leaves like that, I get a stomachache. Why?”

This began a set of questions that lasted nearly two hours.

Secondly, give them time to think. Studies over the past 30 years have shown that. After asking a question, adults typically wait only one second or less for an answer, no time for a child to think. When adults increase their “wait time” to three seconds or more, children give more logical, complete and creative answers.

Thirdly, watch your language. Once you have a child involved in a science discussion, don’t jump in with “That’s right” or “very good”. These words work well when it comes to encouraging good behavior. But in talking about science, quick praise can signal that discussion is over. Instead, keep things going by saying, “That’s interesting” or “I’d never thought of it that way before’, or coming up with more questions or ideas.

Never push a child to “think”. It doesn’t make sense; children are always thinking, without your telling them to. What’s more, this can turn a conversation into a performance. The child will try to find the answer you want, in as few words as possible, so that he will be a small target for your disagreement.

Lastly, show; don’t tell. Real-life impressions of nature are far more impressive than any lesson children can learn from a book or a television program. Let children look at their fingertips through a magnifying glass, and they’ll understand why you want them to wash before dinner. Rather than saying that water evaporates, set a pot of water to boil and let them watch the water level drop.

小题1:According to the passage, children are natural scientist, and to raise their interest, the most important thing for adults to do is______________.

A.to let them see the world around

B.to share the children’s curiosity

C.to explain difficult phrases about science

D.to supply the children with lab equipment小题2:In the last sentence of the first paragraph, the word “list” could best be replaced by ______________.

A.any questions

B.any problems

C.questions from the textbooks

D.any number of questions小题3:According to the passage, children can answer questions in a more logical, complete and creative way if adults______________________.

A.ask them to answer quickly

B.wait for one or two seconds after a question

C.tell them to answer the next day

D.wait at least for three seconds after a question小题4:In which of the following paragraph (s) does the author tell us what to say to encourage children in a science discussion?

A.The 2nd and 3rd

B.The 4th and 5th

C.The 5th and 6th

D.The 7th小题5:The author mentions all of the following techniques for adults to share with their children’s curiosity except that adults should_____________.

A.tell their children stories instead of reciting facts

B.offer their children chances to see things for themselves

C.be patient enough when their children answer questions

D.encourage their children to ask questions of their own

题型:选择题

筒仓式堆肥发酵仓的结构性相对来说比较简单,堆肥原料由仓顶进入,其好氧发酵的时间一般是(),初步腐熟的堆肥由仓顶通过出料机出料。

A.7~15天

B.6~12天

C.10~12天

D.4~5天

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