【单选题】【消耗次数：1】
重金属检查中，加入硫代乙酰胺时溶液的最佳pH值是
①
2.5
②
3.5
③
4.5
④
5.5
⑤
7.0
参考答案：
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2015药典中增加控制重金属检测是因为
①
重金属在土壤中沉积，植物可以吸收
②
某些重金属是有毒物质，甚至会致癌
③
重金属在体内不易被排出，形成累积伤害效应
④
很多重金属都是工业原料，会从而造成水和土壤的污染
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阅读课文II.How to Improve Memory,判读正误1. Information kept in short-term memory may last a few years.
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阅读课文II.How to Improve Memory,判读正误2.Information in long-term memory is often kept a longer period of time than that in short-term memory.
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阅读课文II.How to Improve Memory,判读正误3. Your parents address is usually in your long-term memory.
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【单选题】
6. A new house ___ at the corner of the road.
①
is building
②
is being built
③
been built
④
be building
【单选题】
8.Doctors ___ in every part of the world.
①
need
②
are needing
③
are needed
④
will need
【单选题】
3. This English song___ by the girls after class.
①
often sings
②
often sang
③
is often sang
④
is often sung
【单选题】
9.His new book___ next month.
①
will be published
②
is publishing
③
is being published
④
has been published
【单选题】
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①
it sold
②
its selling
③
Its been sold
④
it had been sold