All the __________ blood must be tested for HIV and other infections, which is important for the patients. 【选项
— The room is dirty. — I know. It ______ for several weeks.
I don’t expect the children to be noisy, nor ________ them to be quiet.
It’s difficult to ___ these old books for some of them ______ none of the classification.
Many kinds of animals and plants die _________ every year.
We should do something to _______ the plant ______ the cold weather.