题型:选择题 Let's hurry! There are only two minutes _______. [ ]A. leave B. to leave C. left D. leaving 查看答案
题型:单项选择题 用高压固井泵进行漏失测试。当向钻柱内泵入钻井液并从立压表上读数时,从图1-25中选择阀1,2,3和4的正确位置。()A、1=开,2=关,3=开,4=关.B、1=关,2=开,3=关,4=开.C、1=开,2=开,3=开,4=关.D、1=关,2=开,3=开,4=关. 查看答案