Students in the USA spend ______ time _____their homework than we do.

Progress so far has been very good , we are sure that the project will be completed on time[ ]

21．The doctor couldn’t answer the question _____ the patient could survive that night

Her son _____ Coke, but now he _____ milk.

The old professor told us every part of thematerials should be made use of ______ the power station.