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
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.
单项选择题 After he （） the test, the engineer put down the results.
