资料题：Which of the following is implied but not stated（　）。

Have you ever been afraid to talk beck when you were treated unfairly? Have you ever bought something just because the salesman talked you into it? Are you afraid to ask for a date?Many people are afraid to assent themselves.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 is geared to make people distrust themselves," says Alberti."There's always a 'superior' around-a parent, a teacher, a boss - who 'knows better'.The superiors' often gain when they chip away at your self- image."But Alberti and other scientists are doing something to help people assert themselves.Theyoffer"assertive training" courses-AT for short.In the AT course 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 to overcome fear.A group taking an AT course will help the timid person to lose his fear.But AT uses an even stronger motive-the need to share.The timid person speaks out in the group because he wants to tell how he feels.Whether or not you speak up for yourself depends on your self-image.If someone you face is more"important" than you, you may feel less of a person.You start to doubt your own good sense.You go by the other person's label.But, why should you? AT says you can get t feel good about yourself.And once you do, you can learn to speak out.