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问题 选择题

淀粉溶液是一种胶体，并且淀粉遇到碘单质，可以出现明显的蓝色特征。现将淀粉和稀Na2SO4溶液混合，装在半透膜中，浸泡在盛蒸馏水的烧杯内，过一段时间后，取烧杯中液体进行实验，能证明半透膜完好无损的是

A．加入BaCl2溶液产生白色沉淀

B．加入碘水不变蓝

C．加入BaCl2溶液没有白色沉淀产生

D．加入碘水变蓝

答案

答案：B

胶体是不能透过半透膜的，如果半透膜完好无损，则烧杯中液体中不可能含有淀粉，如果半透膜破损，则淀粉也会存在于烧杯中，故可用碘来检验淀粉的存在（是否变蓝色）来判断半透膜是否完好，答案为B

判断题

胜利油田标准手操器无法连接无线仪表有可能是仪表未激活。（）
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单项选择题

What’s your earliest childhood memory Can you remember learning to walk Or talk The first time you heard thunder or watched a television program Adults seldom (1) events much earlier than the year or so before entering school, (2) children younger than three or four (3) retain any specific, personal experiences.

A variety of explanations have been (4) by psychologists for this "childhood amnesia". One argues that the hippo-campus; the region of the brain which is (5) for forming memories, does not mature until about the age of two. But the most popular theory (6) that, since adults don’t think like children, they cannot (7) childhood memories. Adults think in words, and their life memories are like stories or (8) one event follows (9) as in a novel or film. But when they search through their mental (10) for early childhood memories to add to this verbal life story, they don’t find any that fit the (11) . It’s like trying to find a Chinese word in an English dictionary.

Now psychologist Annette Simms of the New York State University offers a new (12) for childhood amnesia. She argues that there simply aren’t any early childhood memories to (13) . According to Dr. Simms, children need to learn to use someone else’s spoken description of their personal (14) in order to turn their own short-term, quickly forgotten (15) of them into long-term memories. In other (16) , children have to talk about their experiences and hear others talk about (17) --Mother talking about the afternoon (18) looking for seashells at the beach or Dad asking them about their day at Ocean Park. Without this (19) reinforcement, says Dr. Simms, children cannot form (20) memories of their personal experiences.

Notes: childhood amnesia 儿童失忆症。

8（）

A.narratives

B.forecasts

C.communications

D.descriptions
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