单项选择题
If you （） the equipment more carefully before sail, we （） so much trouble now.
A.examined；are not having B.had examined；would not have C.had examined；would not have had D.should examine；would not have
单项选择题 We’ve tried many ways, but all in vainOnly in this way, （） the problem, I’m sure.
单项选择题 Let H （） the quantity of heat which has been converted into mechanical work.
单项选择题 The chief engineer suggests that the second engineer （） a dead line for handing in the work plan.
