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
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.
单项选择题 Now that the valve is not worth （）, I suggest it （）.
