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问题 计算题

小华家买了一个家用电吹风，如图甲所示．其中电动机通电后可以送风，电热丝通电后可以发热．其简化电路如图乙所示，主要技术参数如下表

请回答如下问题：

（1）当开关旋至     、    触点时，电吹风处于吹热风状态．

（2）当电吹风吹冷风状态时，正常工作5min消耗的电能是多少焦？

（3）当实际电压为220V时，电吹风电热丝的实际功率为多大？

（4）为了使电吹风吹出的热风温度更高些，你可以采用爰措施？

（可用文字可作图说明） 

答案

解：（1）A，B；

（2）送冷风时，只有电动机工作，电动机的额定功率是P=90W，通电5min，则电流所做的功W=Pt=90W×5×60s=27000J．

（3）当实际电压为220V时，与电热丝的额定电压220V相等，所以实际功率与额定功率相等，即实际功率是1210W．

（4）为了使电吹风吹出的热风温度更高些，要提高电热丝的功率，

根据P=可知：方法是并联一根电热丝或更换一根阻值较小的电热丝．

问答题

聚苯乙烯可用于制备高频绝缘材料，苯乙烯在我定条件下存在如下图转化关系．

请回答下列问题：

（1）由苯乙烯合成这种高聚物的化学方程式为______．

（2）反应①的反应类型是______，C→D的反应类型是______．

（3）C可能的结构简式有______．

（4）H有多种同分异构体．同时符合下列条件的同分异构体共有______种．

a．与FeCl3溶液发生显色反应      b.1mol H最多能与3mol NaOH反应；c．苯环上只有两个取代基．

（o）反应③的化学方程式是______．
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填空题

1) ______ linguistic competence and linguistic performance
2) ______ assimilation and accommodation
3) ______ the language acquisition device (LAD)
4) ______ communicative competence
5) ______ the input hypothesis
a) The former is the process by which incoming information is changed or modified in our minds so that we can fit it in with what we already know; while the latter is the process by which we modify what we already know to take into account new information.
b) The former refers to knowledge of grammatical rules of language; whale the latter refers to application of language.
c) The ability not only to apply the grammatical rules of a language in order to form grammatically correct sentences but also to know when and where to use these sentences and to whom.
d) A sort of mechanism or device which contains the capacity to acquire one’s first language.
e) It assumes that humans acquire language in only one way--by understanding messages, or by receiving "comprehensible input".
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