题目

Shyness is the cause of much unhappiness for a great many people. Shy people are anxious and self-conscious; that is, they are concerned with their own appearance and actions too much. Negative thoughts are constantly occurring in their minds: What kind of impression am I making? Do they like me? Do I sound stupid? Am I wearing unattractive clothes?It is obvious that such uncomfortable feelings must affect people unfavorably. A person's self-concept is reflected in the way he or she behaves and the way a person behaves affects other people's reactions. In general, the way people think about th7、函数f（x）=x2-2x的单调减区间是（　　）A、（-∞，+∞）B、（-∞，1]C、[1，+∞）D、（-∞，0]