用所给动词的适当形式填空。
If you         (not be) careful with dogs，they may bite you．
My teacher often advises us         (read) English aloud every morning．
The Greens         (visit) Beijing in a week，aren’t they?
Be quiet! Bob with his classmates         (prepare) for the English test．
          (save) water, turn off the tap after you wash your hands．