按照题号写出下列词的 ing 适当形式。 1. clean_______ 2. work_______ 3 . watch_______4 go_______ 5. play_______ 6 study_______ 7.take_______ 8. have__ ______ 9. dance_______10. get_______ 11. run_______ 12. swim_______ 13. sit_______ 14. shop_______ 15. stop_____ 16. arrive _______ 17 begin _______ 18 forget _______