[单项选择]You （　） all those calculations! We have a computer to do that sort of thing.
A. needn’t have done
B. must not have done
C. shouldn’t have done
D. can not have done

[单项选择]You （） all those calculations! We have a computer to do that sort of thing.
A. needn’t have done
B. must not have done
C. shouldn’t have done
D. can not have done

[单项选择]You ______ all those calculations ! We have a computer to do that sort of things.
A. needn’t have done B. shouldn’t have done
C. must not have done D. could not have done

[单项选择]You（）all those clothes by hand! You have a washing-machine to that kind of thing.
A. mustn’t have washed
B. cannot have washed
C. needn’t have washed
D. shouldn’t wash

[单项选择]

Have you ever been afraid to talk back when you were treated unfairly Have you ever bought something just because the salesman talked you into it Are you afraid to ask a boy (girl) for a date
Many people are afraid to assert themselves (insist upon their own rights). Dr. Robert Alberti, author of Stand Up, Speak Out, and Talk Back, thinks it’s because their self-esteem is low. "Our whole set-up makes people doubt themselves, " says Alberti. "There’s always a’ superior’ around—a parent, a teacher, a boss—who ’knows better’".
But Alberti and other scientists are doing something to help people to assert themselves. They offer "assertiveness training" courses (AT). In the AT courses people learn that they have a right to be themselves. They learn to speak out and feel good about doing so. They learn to be aggressive without hurting other people.
In one way, learning to speak out is t
A. make them distrust their own judgment
B. make things more favorable for them
C. keep them from speaking out as much as their superiors do
D. help them to learn to speak up for their rights