Tom ____ better than to ask Dick for help. A) shall know B) shouldn't know C) has known D) should have known 2. You ____ your tooth pulled out before it rot completely. A) had better got B) had to get better C) had better to get D) had better get 3.When we got to the cinema, the film hasn't started yet, so we ____. A) needn't hurry B) didn't need hurry C) needn't to hurry D) needn't have hurried 4. It was really very dangerous; you ____ him seriously. A) might have injured B) could injure C) should have injured D) must injure 5. As he had heart attack, he was told that he ____ continue the work. A) needn't B) may not C) mustn't D) can't