题目

用于制造隐形飞机的某种物质具有吸收微波的功能，其主要成分的结构简式如右图，它属于       A．烃                              B．无机物C．有机化合物                          D．烷烃     答案：C（共5小题，每小题3分，满分15分）根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。选项中有两项是多余选项。You may know the benefits of laughter on the mind and spirit. __1__. Norman Cousins used to say that laughter is so beneficial for your body that is like “inner jogging”. Mayo Clinic Health Letter reports that laughter aids breathing by increasing your breathing rate. It can even help clear mucus (粘液) from your lungs. __2__. It increases circulation and improves the delivery of oxygen and nutrients to tissues throughout your body. __3__. It helps fight off colds, flu etc. by increasing the concentration of immunoglobulin A (免疫球蛋白A) in your saliva (唾液). And it may help control pain by raising the levels of certain brain chemicals. Furthermore, it is a natural stress reliever. Have you ever laughter so hard that you doubled over, feel off your chair, spit out your food? __4__. The good news is that you are allowed more than 15 laughs a day! Go ahead and double the dose and make it 30 times today. (You may begin to notice immediate improvement in your relationships!) Then double it again! __5__. People will enjoy being around you as well. Laughter, it's the best medicine.A. Laughter is also good for your heart.B. A good laugh helps you build up you body to protect against diseases.C. However, it is confusing why laughter makes people so good.D. However, are you aware of how much a good laugh can help you physically?E. A good laugh relieves physical tension and stress.F. You cannot maintain muscle tension when you are laughing!G. You are likely to feel better and deal with problems more effectively.