用下面方框中所给短语的适当形式填空。 such as,       because of,       come up,       make use of,       at present 1. The purpose of this meeting is to discuss how to ______ the used books. 2. The farmer grows vanous kinds of crops, ______ wheat, com, cotton and rice. 3. We don't know why his performance didn't ______ to his usual standard. 4. You should pay more attention to your study ______ because you are a student. 5. They had to stay at home instead of going shopping ______ a heavy rain.