完形填空，阅读下面的短文，掌握其大意，然后从短文后各题所给的A、B、C、D四个选项中，选择最佳选项。

　　A

　　IQ(intelligence quotient智商)is a score that shows a person’s level of intelligence. People used to believe that some people are born with a high IQ and some aren’t.

　1 a study by scientist at University College London has challenged(挑战)this idea. According to an article last October on the Journal Nature, scientists are beginning to think that our IQ is not a constant(不变的)score.

　　The scientists tested 33 healthy young people in 2004 between the ages of 12 and 16. Then they did tests again four years later, when the same people were between 16 and 20.

　　Scientists found big changes in the IQ scores between 2008 and 2004. Some　2and some fell 3 as many as 21 points.

　　To test whether these scores were meaningful, the scientists compared them with results from brain scans(扫描). They found that the IQ changes matched changes in the structure(结构)of the subjects’ brains. “A change in 20 points is a huge 　4 ,” said Professor Cathy Price, who led the research. He said it could mean the difference between an average and a 　5 person. The team has not found a clear cause for these changes. However, they say it is 　6 that education plays a role in changing IQ. “Here we have shown that children’s 　7 is likely to be still developing, ” says Price. “We have to be careful not to write off 　8 performers at an early stage. In fact, their IQ may improve in a few more years. ”

　  1 A. And B. However C. Besides D. Though

　  2 A. rise B. rose C. raise D. raised

　  3 A. of B. with C. by D. from

　　4 A. difference B. matter C. thing D. meaning

　　5 A. successful B. gifted C. able D. rich

　　6 A. natural B. true C. certain D. possible

　  7 A. score B. intelligence C. skill D. interest

　　8 A. clever B. prettier C. nicer D. poorer

　　B

　　As darkness fell, hundreds of people in the Swiss village left their houses. They were staring(注视)forward at the mountain top in the distance. It was covered with ice and snow-beautiful and dangerous.

　　The huge mountain is called Matterhorn. Mountain climbers had 　9 the top through the southern route(路线). But no one had ever dared to try a winter climbing up the northern side. But now one man was daring to try the 10 route. He was Walter Bonatti, a great mountain climber 　11 Italy. For two days he had climbed. The village people had watched him anxiously(焦虑). Now they were waiting to see his signal. If he planned to 　12 the next day, he would light(点燃)a green signal(信号). A red light would mean that he was turning back. A tiny green light 13 high on the mountain side. Bonatti was not giving up! The people 　14. The next day he continued his way upward. He was so lonely and so 　15 ! But he would not give up. Again that night he lit the green light. In the morning, Bonatti 16 . He could not see the top;he knew he was 17there. Though the climb was painful, he moved up. Bonatti had spent months 　18for the climb. Was the training enough? Did he have the strength and skill to climb to the top? He was finally at the top! News about his. 　19 was radioed to the world.

　　The trip down the southern route was easy. He was warmly welcomed in the village. He had done the “ 　20” and would be well remembered as a climber of all time.

　　 9A. reached B. passed C. watched D. followed

　　10A. comfortable B. important C. difficult D. nervous

　　11 A. with B. from C. in D. at

　　12 A. turn back B. come down C. go on D. get back

13A. placed B. appeared C. pulled D. found

　　14 A. cried B. laughed C. jumped D. cheered

　　15 A. sleepy B. excited C. tired D. happy

　　16 A. woke up B. turned up C. got up D. looked up

　  17 A. already B. almost C. hardly D. surely

　  18A. training B. practising C. planning D. asking

　  19 A. importance B. success C. climb D. courage

　  20A. necessary B. dangerous C. perfect D. impossible