题型:阅读选择 题类:常考题 难易度:普通
四川省成都市金牛区2017-2018学年七年级下学期英语期末测试试卷
When you are doing homework, sometimes your eyes may suddenly twitch (抽动). You may hear some superstitions (迷信) about this. For example, if your right eye jumps, you will hear good news. If your left eye jumps, you will hear bad news.
But science can tell you that it has nothing to do with these superstitions. It is just a movement of your muscles (肌肉). There are a few reasons why this happens.
According to ZME Science, when you feel stressed or tired, your eyes will twitch. This tells you that you need to get more rest.
Looking at a TV or computer screen for a long time can also make your eye twitch. Looking at screens can make your eye dry (干涩的). So it twitches to make itself wet.
Lacking(缺乏) some minerals (矿物质) in your diet(饮食) is another reason. Eating food such as almonds (杏仁) or spinach (菠菜) can be helpful.
The human spine(脊柱) doesn't just help us stand up straight. Inside the spine is the spinal cord (脊髓) {#blank#}1{#/blank#} The legs and feet send "sense" information to the brain, saying they're hurt or hot, for example. And the brain sends messages to the lower body, telling the legs to walk, dance or sit down.
When someone's spinal cord is hurt, information about senses doesn't reach the brain from the lower body. And control messages can't make it to the lower body from the brain. {#blank#}2{#/blank#}
Surprisingly, now scientists in Switzerland have given three paralyzed men the ability to walk again. All of the three men had damaged their spinal cords in motorcycle accidents and couldn't move their legs. To help them walk again, a special device (装置) was put directly on the lower part of their spinal cord.
The scientists controlled the device from a computer. {#blank#}3{#/blank#} In the past, scientists have had some successes with the similar device in the lower spine. Some patients have even trained themselves over months to be able to walk.
But this research is different. {#blank#}4{#/blank#}Instead, the computer tells the device to send "walking" messages. The scientists use computers to create patterns of movement—like taking a step—that work well with each patient. The patients then choose the pattern they want, and the muscles (肌肉) move in the chosen way.
Over time, the three men are able to walk on their own, using a special walker with buttons to trigger (激发) each leg. {#blank#}5{#/blank#} The scientists are hopeful that in the future, this technology will allow more paralyzed people to walk again.
A. When that happens, a person is paralyzed (瘫痪的). B. The patients' brains aren't sending "walking" messages to their legs. C. The solution isn't perfect and the patients can't walk without the system. D. One of them has walked for half a kilometer on his own with the walker. E. It carries important information between the head and the lower part of the body. F. Just hours after the device was first used, all the three men were taking steps, with support. |
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