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Watching too much television is bad for your eyes. This is not true. People with easily affected eyes may find they get red and aching from staring at a fixed distance for long periods, but there won’t be any lasting effects.
Carrots will help you see in the dark. Carrots are rich in beta carotene, which the body can change into vitamin A, too little of which can cause night blindness. However, people in most countries don’t need to worry about vitamin A deficiency(缺乏). Night blindness is more likely to be connected with another vision problem.
1. According to the passage, which of the following is true?
A. Ready-made glasses will do harm to one’s eyes.
B. Wearing the wrong glasses may do harm to children’s eyes.
C. The human body is unable to change beta carotene into vitamin A.
D. Watching too much television may do harm to children’s eyes.
2. Night blindness is most likely caused by ______.
A. staring for long periods
B. too much beta carotene
C. not enough vitamin A
D. vision problems
3. According to the article, eye problems can be corrected by ______.
A. wearing specially-made glasses
B. performing eyes exercises
C. cutting back on television
D. eating more carrots
4. Watching too much television can cause ______.
A. night blindness
B. lasting eye problems
C. a number of vision problems
D. eye trouble for a limited time
5. The main purpose of this article is to ______.
A. tell people of the importance of their eyes
B. tell people how to protect their eyes
C. tell people to have more carrots
D. tell people something more about their eyes
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Wearing the wrong type of glasses will do harm to your eyes. This is not true for adults(成人), although incorrect glasses may not be good for children under 10. Ready-made glasses, and not wearing glasses when you should, won’t do harm to your eyes, but you may see better with glasses that are specially made for you.
Watching too much television is bad for your eyes. This is not true. People with easily affected eyes may find they get red and aching from staring at a fixed distance for long periods, but there won’t be any lasting effects.
Carrots will help you see in the dark. Carrots are rich in beta carotene, which the body can change into vitamin A, too little of which can cause night blindness. However, people in most countries don’t need to worry about vitamin A deficiency(缺乏). Night blindness is more likely to be connected with another vision problem.
1. According to the passage, which of the following is true?
A. Ready-made glasses will do harm to one’s eyes.
B. Wearing the wrong glasses may do harm to children’s eyes.
C. The human body is unable to change beta carotene into vitamin A.
D. Watching too much television may do harm to children’s eyes.
2. Night blindness is most likely caused by ______.
A. staring for long periods
B. too much beta carotene
C. not enough vitamin A
D. vision problems
3. According to the article, eye problems can be corrected by ______.
A. wearing specially-made glasses
B. performing eyes exercises
C. cutting back on television
D. eating more carrots
4. Watching too much television can cause ______.
A. night blindness
B. lasting eye problems
C. a number of vision problems
D. eye trouble for a limited time
5. The main purpose of this article is to ______.
A. tell people of the importance of their eyes
B. tell people how to protect their eyes
C. tell people to have more carrots
D. tell people something more about their eyes
查看习题详情和答案>>
Researches at Johns? Hopkins University's. Applied Physics laboratory? ( APL)? in Laurel , Maryland have designed a new human-like robot, Its name is Robo Sally. The machine can be controlled from a distance and can he used to do work that is dangerous for human beings.
?????? Roho Sally has two long arms with human-like hands. She can use her fingers to pick up? small objects .examine them in detail and do most things that human hands can do Each finger? contains a tiny motor capable of squeezing 20 pounds of pinch foree ,.enough to defuse a bomb? under the direction of an operator. She sits on a metal base with wheels that let her move around. turn in tight spaces and climb over small objects, .
?????? Mike McLoughlin is the main investigator for the Applied Physics Laboratory's Prosthetics? Program. "The purpose of that program is to develop prosthetic arms that have all the capability? of your natural arms .and you do all the complex motions that we can do with the natural arm- with the robot. "
?????? It was a difficult job. Mr. McLoughlin says the device had to have many small motors to。 have the ability to do what a human hand does; It? also needs to have human-like strength. The? thumb was especially difficult because it permits the hand .to hold objects. And everything had.?? to fit into a space about the size of a human hand.
????? The next problem? .he says .was to figure out how to control the artificial hand. " So we had?? to figure out how to make the connection between the brain and this arm.
?????? For search-and-rescue duties.Roho Sally will be operated by a human being using a wire- less machine that is far from the robot. The operator will also wear special gloves and glasses.? The glasses permit the operator to see the robot's hands .even though they are far away.
????? Mr. McLoughlin says this kind of robots could be used in what he calls "dull , dirty or dan- gerous" situations where fine human finger movements are required. He says the technology is? not ready for everyday application .but he predicts that within five years we will see some won-? derful improvements.
1.The underlined word " defuse"? in Paragraph 2 is closest in meaning to "_________".
A. remove?????????? B. discover??????????? C. equip??????????????? D. produce
2.According to Paragraph 2.which picture is Robo Sally?
3.What can we learn ahout the prosthetic arms according to the passage?
A. They are expected to function as well as natural ones.
B. They have many large motors controlled by robots.
C. They have human-like strength to control the robot.
D. They are connected with human brains.
4.Which of the following is true about Robo Sally according to Mr. McLoughlin?
A . Its operator doesn't need? any? equipment.
B. It has been Widely used in everyday life in the USA.
C. It can work in situations which are dangerous for humans.
D. It has made much money for the designer.
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