题目

长期不正确用眼，会使眼球结构发生变化导致近视眼，以下属于近视眼成因的是A．眼轴前后径过短 B．眼轴前后径过长C．晶状体曲度过小 D．晶状体曲度过大 答案：【答案】BD【解析】试题长时间的近距离作业，如读书写字、看电视、玩游戏机等，使眼睛长时间的调节紧张，头部前倾，眼球内不断的充血，眼内压相应的增高，以及眼外肌的紧张和压迫眼球，导致晶状体过度变凸，不能恢复成原状，严重时使眼球的前后径过长，使远处物体反射来的光线形成的物像The word doping is probably from the Dutch word dop, the name of an alcoholic drinks make of grape skins used by Zulu soldiers in order to encourage their bravery in battle. The term became current around the turn of the 20th century, originally referring to illegal drugging of racehorses. In 1928 the International Amateur Athletic Federation (IAAF) became the first to ban the use of doping. A reliable test method was finally introduced in 1974.The practice of enhancing athletes’ performance through foreign substance or other artificial means, however, is as old as competitive sport itself. The most famous doping case of the 1980s concerned Ben Johnson, the 100-meter champion who tested positive for stanozolol(司坦咗醇) at the Olympic Games in Seoul, 1988.The main front in the anti-doping war has rapidly shifted to blood doping since 1970s. Blood doping is the practice of adding red blood cells to the bloodstream in order to improve athletes’ performance. The blood is usually processed in order to create a concentration of red blood cells, and then freeze them until needed for transfusion(输血) back into the athlete shortly before the event. The extra red blood cells will deliver more oxygen and other essential elements to the athlete’s muscle tissues.Just like any other problem, the only way to solve it is through education. Many high school sports programs now have people come in to talk to them about out the dangers of performance-enhancing drugs. Young players must be fully clear on the rules and what substances are banned. The NCAA (National Collegiate Athletic Association) has an easily accessible list of what substances are banned, how they are tested for and why they are banned on its website. This way, young players are clear on what they can put in their bodies. This is also a good way to educate players on the danger of the substances they may be tempted to use.小题1:The word “enhancing” in the first sentence of the second paragraph means “_____”.A．showingB．directingC．upsettingD．improving小题2:What can we know from the third paragraph?A．Blood doping is transferring one man’s blood into anotherB．Only blood doping exists in the anti-doping war in the 1970s.C．Blood doping is easy to be found and controlled by organizations.D．More oxygen in the blood helps improve an athlete’s performance.小题3:The word “people” in the second sentence of the fourth paragraph probably refers to _____.A．teachers who teach P.E. lessons at schoolB．experts who do research in dopingC．young people easy to be addicted to dopingD．athletes involved in doping小题4:Which statement best matches the last paragraph?A．Prevention is better than cure.B．Reading is to the mind what exercise is to the body.C．The best horse needs breaking, and the cleverest child needs teaching.D．A little learning is a dangerous thing.