Where to get the materials and how to get them ________ at the meeting.
A. have not discussed
B. have not been discussed
C. has not discussed
D. has not been discussed
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I like mathematics and physics because I think that ________ very important for me to make further research in this field.
A. what is
B. they are
C. this
D. which are
Every student and every teacher ________.
A. are going to attend the meeting
B. have attended the meeting
C. has attended the meeting
D. is attended the meeting
流量换算关系, 1m3 /s等于
A. 60 L/min
B. 600 L/min
C. 6×104 L/min
D. 1000 L/min
当温度升高时,油液的粘度:
A. 下降
B. 增加
C. 没有变化
D. 不一定
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