11. sometime—sometimes 12. on—up 13. 去掉 not 14. 正确15. 去掉第一个to 16. them—it 17.making—make 18.whom—who 19. send—sent 20. takes place---takes the place
略
11. sometime—sometimes 12. on—up 13. 去掉 not 14. 正确15. 去掉第一个to 16. them—it 17.making—make 18.whom—who 19. send—sent 20. takes place---takes the place
略