69. The main purpose of this passage is ___.
A. to offer young people a fun - filled holiday
B. to attract young people to attend a conservation camp
C. to persuade people into exploring the countryside
D. to raise funds for the International Conservation Scouts
70. According to the passage, you can ___ at the conservation camps.
A. experiment on the dormouse B. practise your favorite hobbies
C. enrich your knowledge of wildlife D. have free accommodation and food
71. Judging from the writing style of the passage, it is ___.
A. a piece of advertisement B. a science report
C. a passage for professional reading D. a passage for arguing an opinion
( C )
In some children who go blind, certain parts of the brain that normally control vision appear to switch jobs and focus instead on sound, a new study has found.
The study, by researchers at the University of Montreal, involved 7 adults who could see and 12 adults who had lost their vision when they were children. Each participant sat in a room with 16 loudspeakers at different locations. The room was designed so that there were no echoes. During the experiment, the speakers irregularly produced sounds. Participants had to point to where the sounds were coming from. Meanwhile, the researchers monitored blood flow in the brains of the participants to see which brain structures were working during the task.
The results showed that five of the blind participants were very good at pointing to where sounds were coming from. In these people, blood flow increased in the visual cortex- an area at the back of the right side of the brain. This part of the brain is usually associated with vision.
The other seven blind participants showed no increase in activity in the visual cortex. These people didn't do very well at picking out where sounds were coming from. Now, the researchers are looking at whether these people have gained an enhanced sense of touch instead of sound to replace their lost vision.
The scientists say that their study shows how adaptable parts of the brain can be.