油罐装油完毕后,要静止一段时间方可计量、取样。5000m3油罐,静止时间为()。
A.30min到60min
B.10min左右
C.1min左右
D.20min左右
参考答案:A
A fork and knife ____ on the table. [ ]
A. is
B. are
C. has been
D. have been
经济周期的衡量中,当实际产出连续( )年下降,而实际GDP与潜在GDP之间的缺口并不大时,经济的下降被称作衰退。
A.1~2B.1~3C.2~3D.3~5