题目

下列说法中，正确的是（ ） A．命题“若am2＜bm2，则a＜b”的逆命题是真命题 B．命题“存在x∈R，x2﹣x＞0”的否定是：“任意x∈R，x2﹣x≤0” C．命题“p或q”为真命题，则命题“p”和命题“q”均为真命题 D．已知x∈R，则“x＞1”是“x＞2”的充分不必要条件 答案：B考点】命题的真假判断与应用． 【专题】简易逻辑． 【分析】A．原命题的逆命题是“若a＜b，则am2＜bm2”是假命题，由于m=0时不成立； B．利用“全称命题”的否定是“特称命题”即可判断出正误； C．由“p或q”为真命题，可知：命题“p”和命题“q”至少有一个为真命题，即可判断出正误； D．x∈R根据短文判断下面句子的正确(T)与错误(F) 。     Are you too nervous to work out the problem when your teacher asks you to come to the blackboard? If your answer is "yes", you get really shy.      Shyness means feeling frightened when you're the center of attention (注意力). In fact, everybody gets a little shy sometimes, even the great people in history. When Thomas Edison was young, he loved Shakespeare (莎士比亚) very much. He wanted to act in his play. But he was too shy. He didn't know what to do when there were people around. Later, he had to give up. But shyness didn't stop him from becoming a great inventor.      Some experts say shy people are cleverer because they think more and talk less. Shy people are also good at working with others because they think more for other people. Most people have red faces and talk in broken sentences (语句支离) when they get shy. It isn't a very big problem. But some become so shy that they can't do the things they want to do. This kind of shyness can be bad for a person. Here are some good ways to make you braver (勇敢).      ●Tell people you are shy. This can make others understand you better and help you easier in talks.      ●Try to smile more. People think you are friendly and easy to talk to when you smile.      ●Learn to be a good talker. Begin your talk with saying something nice about people around you. It's very helpful for keeping your talk.      ● Put your attention somewhere else. Think more about ways to enjoy the party or the game. Don't waste time worrying about your looks or whether people like you or not. (     )1. Sometimes everyone gets a little shy.                                                           (     )2. Thomas Edison became a great inventor because he never felt shy.                                 (     )3. This passage (短文)  didn't say if Shakespeare was shy.                                          (     )4. Some experts say that shy people are cleverer than others.                                       (     )5. Shy people can't work well with others.                                                          (     )6. Some people are too shy to do what they want to do.                                              (     )7. If you are a shy person, you should let people know this when you talk to them.                  (     )8. To begin a talk, you'd better say something good about yourself. This can help you feel less shy.(     )9. At a party, you should think more about whether people like you or not.                          (     )10. You can find some good ways to make you braver from the passage.