题目内容
(请给出正确答案)
[单选题]
D001SY£¯T5184—1997《油、气、水井防砂作业用石英砂》中规定的标准振筛机的振动次数为()min1。
A.221
B.147
C.293
D.250
答案
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A.221
B.147
C.293
D.250
第1题
Between 1974 and 1997,the number of overseas visitors expanded______ 27%.
A) byB) forC) toD) in
第2题
tors expanded _________27%.
A) by B) for
C) to D) in