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【简答题】
对影响钢材性能的因素中化学成分的影响，下列叙述正确的是()。 (A) Mn，Si是有益元素，Al和S是有害元素 (B) Mn，Si，V，N是有益元素，Al，P和S是有害元素 (C) Mn，Si，A1是有益元素，S，P是有害元素 (D) Mn，Si是有益元素，S，P，O是有害元素
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举一反三
【简答题】文献是指记录有 的 。
【单选题】What about the distinction between violent acts and non-violent ones in sports?
A.
It's impossible to make.
B.
It's too obvious to escape observation.
C.
It's not very clear in any circumstances.
D.
It's not very difficult to make if enough attention is aid to it.
【简答题】文献是指记录有()的载体。
【简答题】拍打;薄片;封盖;振动
【单选题】听力原文：W: So, what special needs do business travelers have? M: [10] One of the most important things is a quick check-in and check-out. Room service is also very important. [7]Guests often stay in thei...
A.
because it is cheaper than in the restaurant.
B.
so they can do more work.
C.
so they can watch TV while they eat.
D.
because they are tired after the long trip.
【简答题】By way of conclusion the author emphasizes that in designing advertisements, the most important factor that has to be considered is
【单选题】— What sort of car do you want to have? An expensive one? — Well,it _____ be expensive-that's not important. [ ]
A.
mustn't
B.
needn't
C.
can't
D.
won't
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