题目内容

【题目】Babies born in summer are more likely to become short-sighted in late life, a study has shown.

As many as a quarter of all cases of short-sightedness are caused by too great an exposure to sunlight in the first weeks of life, say eye experts.

They are advising all parents to put sunglasses on their babies during the first weeks.

Scientists had already established that over-exposure to sunlight caused shortsightedness in animals.

Researchers who compared the months in which babies were born with whether they needed glasses later on say the principle also applies to humans.

A study of almost 300,000 young adults-the largest of its kind-showed that those born in June and July had a 25 per cent greater chance of becoming severely short-sighted than those born in December or January.

Research leader Professor Michael Belkin, of Tel Aviv University, said it was because prolonged illumination(光照) causes the eyeball to lengthen-causing short-sightedness.

Hence the more light a newborn is exposed to, the more the eyeball lengthens and the worse the short-sightedness will be.

The mechanism which lengthens the eyeball is associated with levels of melatonin(褪黑激素), a pigment (色素) which protects the skin against harmful rays of the sun.

In young babies not enough melatonin is released as protection, meaning they are more vulnerable to sunburn and changes to eyeball shape.

Sight expert Professor Daniel O’Leary, of Anglia Ruskin University in Cambridge, said “At the moment we don’t know the precise cause of why light exposure affects sight, but the evidence seems to prove that it is one of the reasons for people becoming shortsighted.”

1Babies born in summer are more likely to be shortsighted ____________.

A. because the summer sun is too strong for babies

B. because babies born in summer have lengthened eyeballs

C. if they are exposed too much sunlight in the first weeks after they are born

D. if parents don’t know a proper way to protect their babies’ eyes

2Melatonin is a kind of material to ___________.

A. prevent the eyes from becoming near-sighted

B. protect the skin from harmful sun rays

C. make our body strong

D. protect babies’ eyes from summer sun

3】From what Professor Daniel O’Leary says we can conclude that ___________.

A. there is no evidence that shortsightedness is related to exposure to sunlight

B. whether light exposure affects sight still needs to be further proved

C. he believes that light exposure can cause shortsightedness

D. he tries to give the cause of why light exposure affects sight

4】The underlined word “vulnerable” in the passage probably means __________.

A. easy to be harmed B. resistant

C. protective D. changeable

答案

1C

2】B

3C

4】A

解析

试题解析:研究表明在夏季出生的婴儿长大后更容易成为近视眼,眼科专家称多达四分之一的近视眼病例是由于在出生后前几周里暴露阳光太久造成。

1细节理解题。根据第一段和第二段得知,眼科专家称:在夏季出生的婴儿长大后更容易成为近视眼,因为由于婴儿在出生后前几周里暴露阳光太久造成。故选C

2推理判断题。根据倒数第三段The mechanism which lengthens the eyeball is associated with levels of melatonin(褪黑激素), a pigment (色素) which protects the skin against harmful rays of the sun.得知,褪黑激素是一种可以保护皮肤不受阳光紫外线伤害的色素。故选B

3推理判断题。根据最后一段得知,剑桥大学的视学专家Daniel O’Leary教授相信暴露在阳光下会导致人们近视眼。故选C。

4猜测词义题。在婴幼儿时期,没有产生足够的褪黑激素作为保护,婴幼儿更容易被阳光灼伤,并且改变眼球的形状。故选A

练习册系列答案
相关题目

【题目】Fear and its companion pain are two of the most useful things that man and animals possess if they are used. If fire didn’t hurt when it burned, children would play with it until their hands were burned away. Similarly, if pain existed but fear didn’t, a child could burn itself again and again because fear would not warn it to keep away from the fire that had burnt it before. A really fearless soldier—and some do exist—is not a good soldier because he is soon killed; and a dead soldier is of no use to his army. Fear and pain are therefore two guards without which man and animals might soon die out.

In our first sentence we suggested that fear ought to be properly used. If, for example, you never go out of your house because of the danger of being knocked down and killed in the street by a car, you are letting fear rule you too much. The important thing is not to let fear rule you, but instead, to use fear as your servant and guide. Fear will warn you of dangers; then you have to decide what action to take.

In many cases, you can take quick and successful action to avoid the danger. For example, you see a car coming straight towards you; fear warns you, you jump out of the way, and all is well.

In some cases, however, you decide that there is nothing that you can do to avoid the danger. For example, you cannot prevent an airplane crashing into your house, and you may not want to go and live in a desert where there are no airplanes. In this case, fear has given you its warning, you have examined it and decided on your course of action, so fear of the particular danger is no longer of any use to you, and you have to try to overcome it.

【1Children would play with fire until their hands are burnt away if _________.

A. they were not well educated at school

B. they had never played with fire before

C. they had no sense of pain

D. they were fearful of pain

【2People sometimes succeed in timely avoiding danger because _________.

A. they have gained experience

B. they are warned of the danger and take quick action

C. they jump out of the way in time

D. they are calm in face of danger

【3What is implied but not stated in the passage?

A. Too much fear is harmful

B. Fear is always something helpful

C . Fear is something that can be avoided

D. Fear ought to be used as our guide in our life

【4The best title for this passage should be __________.

A. No Pains, No Gains B. Pain and Actions

C. The Value of Fear D. The Reason Why People Fear

【题目】Tuvalu, a tiny country in the Pacific Ocean, has asked for help as it fears it will be swallowed up by the sea. Storms and huge waves are a constant threat and none of Tuvalu’s nine little islands is more than five meters above sea level. Salt water is already entering the country’s drinking water supply, as well as damaging plants that produce fruit and vegetable. 1

2 Venice(威尼斯), a historic city in Italy best known for its canals, has sunk about 24 cm over the past 100 years. Experts say that it will have sunk another 20 cm-50 cm by 2050. A century ago, St. Mark’s Square, the lowest point in the city, was flooded about nine times a year. Nowadays, it happens more than 100 times. While Venice is slowly sinking into the mud on which it stands, Tuvalu’s rising sea level is caused by global warming.

The average global temperature has increased by almost 0.5 centigrade degree over the past century; scientists expect it to rise by extra 1-3 degrees over the next 100 years.

Warmer weather makes glaciers(冰川)melt, adding more water to the ocean. The warmer temperatures also make water expand, so it takes up more space, causing the sea level to rise. The sea level has risen about 10 cm-25 cm in the last 100 years.

3

Through burning coal, oil and gas, people have been increasing the greenhouse gases in the atmosphere, such as CO2. This adds to the power of the greenhouse effect, making the planet even warmer.

Many scientists believe that, if the warming is not stopped, there will be huge climate change. 4

5 , the sea will swallow up millions of homes and the world will be flooded with "climate refugees" looking for somewhere to live.

A. The main cause of global warming is human pollution.

B. Should this come true

C. Without urgent help, the country’s days are numbered.

D. But Tuvalu is not the first place to face sinking into the sea.

E. The sea level could rise by one meter this century.

F. People face a lot of pollution.

G. Much has been done about our planet.

违法和不良信息举报电话:027-86699610 举报邮箱:58377363@163.com

精英家教网