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课外小组的同学从某工厂收集到一些混有少量小铁片的细小铜片． （1）为了除去混合物中的铁，同学们预想出三种方法： 方法一：用磁铁． 该方法属于 ______（填“物理”或“化学”）方法； 方法二：用稀硫酸．该方法还可以制得的气体是 ______． 方法三：用硫酸铜溶液．请写出该方法涉及到的化学方程式及基本反应类型：化学方程式 ______，反应类型 ______． （2）上述第 ______种方法操作最简便． （3）在实际操作中，同学们发现“方法三”不能在短时间内将铁除净，请回答其中的原因．
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【单选题】The food we eat seems to have profound effects on our health.Although science has made enormous steps in making food more fit to eat ,it has, at the same time,made many foods unfit to eat. Some resear...
A.
Because of science , diseases caused by polluted food haven been virtually eliminated.
B.
It has caused a lack of information concerning the value of food.
C.
Because of the application of science,some potentially harmful substances have been added to food.
D.
The scientists have preserved the color of meats,but not of vegetables.
【多选题】Topic sentence: The amount of alcohol a person consumes has been found to depend on a number of socioeconomic factors such as age, sex, ethnic background and occupation.
A.
Some religions prohibit consumption altogether, and most encourage moderation.
B.
People in a lower socioeconomic level drink more than people in a higher socioeconomic level.
C.
In some cultures drinking is common at meals, but these same cultures disapprove of drunkenness .
D.
Farm owners have the highest proportion of nondrinkers, while professionals and businessmen have the highest proportion of drinkers.
【单选题】Emperor Charlemagne of the Franks was crowned in 800 A.D.The Frankish Empire at that time extended over what is now Germany, Italy, and France. Charlemagne died in 814, but his briefreign marked the d...
A.
Cultural traditions function to identify members of a culture to one another and, also,to allow the individual to self-identify.
B.
Many of the traditions of these cultures remained active in Frankish society for centuries.
C.
When tradition is lacking or is not honored by the younger generation in a society, there is danger that the culture will be lost.
D.
It is unnecessary to discuss the origin ofthese traditions;it will only muddy the water.
【单选题】This division of science into two distinct cultural traditions, located in different types of institution, is highly______, but in recent years these two cultures have begun to______one another.
A.
influential… disregard
B.
unlikely… join
C.
suspect… benefit
D.
propitious … separate from
E.
pronounced … merge with
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