题目

下列物质由分子构成的是（ ）A. 金刚石 B. 铁 C. 氯化钠 D. 氧气 答案：【答案】D【解析】A、金刚石属于固态非金属单质，是由碳原子直接构成的，不符合题意；B、铁属于金属单质，是由铁原子直接构成的，不符合题意；C、氯化钠是由钠离子和氯离子构成的，不符合题意；D、氧气属于气态非金属单质，是由氧分子构成的，符合题意。故选D。阅读理解 　　Stephen Hawking was born in Oxford, England on 8th January 1942. He went to school in St. Albans -- a small city near London. Although he did well, he was never top of his class. After leaving school, Hawking went first to Oxford University where he studied physics, then he went to Cambridge University where he studied cosmology. As he himself admits (承认) , he didn't work hard. He was a very lazy student, and did very little work. However, he still got good marks.     It was at the age of 20 that Hawking first noticed something was wrong with him. He started to bump (撞上) into things. When he visited his family at Christmas time, his mother was so worried that she made him see a doctor. Hawking was sent to hospital for tests. Finally, the result came back. Hawking had motor neuron disease, an incurable ill- ness which would make him unable to speak, breathe (呼吸) or move without the help of a machine. Doctors said they had no way to help him. He would die before he was 23. 　　At first, Hawking became very depressed (忧伤的) . After a while, though, he began to see his life in a different way. As he later wrote,“Before my illness was diagnosed (诊断) , I had been very bored with life. There had not seemed to be anything worth doing. But shortly after I came out of hospital, I suddenly realized that there were a lot of worthwhile things I could do.”Hawking married, found a job at Cambridge University, and had three children. He also went on to do some of the most important scientific research. 　　Today, Hawking still works at Cambridge University as a professor. He strongly believes that his story shows that nobody, how- ever bad their situation (处境) is, should lose hope.“Life is not fair,”he once said.“You just have to do the best you can in your own situation.” (1) As a university student, Stephen Hawking ________. [　　] A. worked very hardB. studied maths and physics C. was the best student in his classD. was lazy and did very little work (2) Hawking first noticed something was wrong with him when ________. [　　] A. he was sent to hospital for tests B. his mother made him see a doctor C. he was twenty D. he visited his family at Christmas time one year (3) In this passage the word “incurable” means ________ [　　] A. 无法治愈的B. 难以确诊的 C.常见的D.可以治愈的 (4) When Hawking was first diagnosed with motor neuron disease, he ________ [　　] A. made up his mind to get married B. began to see his life in a different way C. thought that nothing in life was worth doing D. became very sad (5) What would be the best title (题目) for this passage? [　　] A. Motor Neurone Disease B. Life is Fair C. Professor Stephen Hawking D. A Lazy Boy