单项选择题
A.in which B.on which C.by which D.from which
If you （） the equipment more carefully before sail, we ...
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
We’ve tried many ways, but all in vainOnly in this way,...
单项选择题We’ve tried many ways, but all in vainOnly in this way, （） the problem, I’m sure.
A.can we solve B.we can solve C.we will solve D.can we solved
Let H （） the quantity of heat which has been converted ...
单项选择题Let H （） the quantity of heat which has been converted into mechanical work.
A.represent B.represents C.representing D.being represented
