用所给动词正确形式填空
 They often ________ (do) their homework at school.
 Look! The cat _____________ (run)up the tree.
 Let's _________ (have) supper.
 Thank you very much for _____________ (give) me a very nice bag.
 He would like __________ (go) shopping.
 Listen ! The children____________ ( sing ) in the classroom.
 He ____________ (not speak ) Chinese.
 Mary likes___________( read ) very much.
 The animal usually sleeps and ________（relax）20 hours every day.
 I want ___________ (work) in a post office.