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【单选题】
在一次渗流实验中,一定物质的量的未知气体通过小孔渗向真空,需要的时间为5s;在相同条件下相同物质的量的氧气渗流需要20s。则未知气体的相对分子质量应是A.
2
B.
4
C.
8
D.
16
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【单选题】-- He was given a free five-day trip to Hainan. -- He _______ it since he has worked so hard.
A.
insists
B.
gets
C.
deserves
D.
receives
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【单选题】_____ to make a breakthrough in his career, he worked day and night in the company. [ ]
A.
Determined
B.
To have determined
C.
Have determined
D.
Having been determined
【简答题】Once upon a time there was a farmer worked hard in the fields 1. every day. One day, while he was ploughing the fields, he heard a 2. bumping sound. He saw a rabbit lie by the trump. He picked i...
【单选题】. He worked day and night, and therefore he _______ buy the sports car.
A.
could
B.
was able to
C.
might
D.
would
【单选题】— How did Jim pass the exam? —He worked day and night for two months. ______, he passed it.
A.
in the way
B.
by the way
C.
on the way
D.
in this way
【单选题】Tom says he wont forget the day______ we worked together and the day ______ we spent together.
A.
when; which
B.
what; that
C.
which; when
D.
on which; when
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