【单选题】【消耗次数：1】
测定工业用水中的总硬度时，用氨性缓冲溶液调节水样pH为（）。
①
9
②
10
③
12
④
13
参考答案：
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相关题目
【多选题】
选择缓冲溶液时应注意
①
所选用的缓冲溶液不能与反应物、生成物发生作用
②
选择适当缓冲对，使缓冲容量接近极大值
③
选择适当的总浓度，浓度一般在0.05-0.2mol/L之间
④
最后用pH计加以校准
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①
essential
②
confusing
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awful
④
puzzled
【单选题】
Things never went _____ as we had expected
①
so smoothly
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smooth
③
so smooth
④
smoothly
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Everyone of them _______ tired and wanted a good rest.
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seems
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is seemed
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was seemed
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seemed
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I don’t know.
②
The movie is very interesting.
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That sounds good.
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The movie is very boring.
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essential
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embarrass
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elementary
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without
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besides
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except
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prize
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rain
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pressure
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①
That’s too bad
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I’m sorry
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I beg your pardon
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That’s great
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①
broken
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harmed
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injured
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enable