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 short-sightedness 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 short-sighted.”

1.    Babies born in summer are more likely to be short-sighted ____________.

       A. because the summer sun is too strong for babies

       B. because babies born in summer have lengthened eyeballs

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

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

2.    Melatonin 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 short-sightedness 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 short-sightedness

       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

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 short-sightedness 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 short-sighted.”
55. Babies born in summer are more likely to be short-sighted ____________.
A. because the summer sun is too strong for babies
B. because babies born in summer have lengthened eyeballs
C. if they are exposed to much sunlight in the first weeks after they are born
D. if parents don’t know a proper way to protect their babies’ eyes
56. Melatonin 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
57.   From what Professor Daniel O’Leary says we can conclude that ___________.
A. there is no evidence that short-sightedness 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 short-sightedness
D. he tries to give the cause of why light exposure affects sight
58.   The underlined word “vulnerable” in the passage probably means __________.
A. easy to be harmed                          B. resistant
C. protective                                     D. changeable

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 short-sightedness 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 short-sighted.”

1.    Babies born in summer are more likely to be short-sighted ____________.

      A. because the summer sun is too strong for babies

      B. because babies born in summer have lengthened eyeballs

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

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

2.    Melatonin 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 short-sightedness 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 short-sightedness

      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

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 short-sightedness 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 short-sighted.”

55. Babies born in summer are more likely to be short-sighted ____________.

      A. because the summer sun is too strong for babies

      B. because babies born in summer have lengthened eyeballs

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

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

56. Melatonin 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

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

      A. there is no evidence that short-sightedness 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 short-sightedness

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

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

      A. easy to be harmed                           B. resistant

      C. protective                                      D. changeable

Medical drugs sometimes cause more damage than they cure. One solution to this problem is to put the drugs inside a capsule, protecting them from the body—and the body from them—until they can be released at just the right spot. There are lots of ways to trigger(引发) this release, including changing temperature, acidity, and so on. But triggers can come with their own risks—burns, for example. Now, researchers in California have designed what could be a harmless trigger to date: shining near-infrared light (NIR,近红外线) on the drug in the capsule.
The idea of using light to liberate the drug in the capsule isn't new. Researchers around the globe have developed polymers (聚合物) and other materials that begin to break down when they absorb either ultraviolet (UV,紫外线) or visible light. But tissues also readily absorb UV and visible light, which means the drug release can be triggered only near the skin, where the light can reach the capsule. NIR light largely passes through tissues, so researchers have tried to use it as a trigger. But few compounds(化合物) absorb NIR well and go through chemical changes.
That changed last year when Adah Almutairi, a chemist at the University of California, San Diego, reported that she and her colleagues had designed a polymer that breaks down when it absorbs NIR light. Their polymer used a commercially available NIR-absorbing group called o-nitrobenzyl (ONB). When they catch the light, ONB groups fall off the polymer, leading to its breakdown. But ONB is only a so-so NIR absorber, and it could be poisonous to cells when it separates from the polymer.
So Almutairi and her colleagues reported creating a new material for capsules that's even better. This one consists of a long chain of compounds called cresol groups linked in a polymer. Cresol contains reactive(易反应的) components that make it highly unstable in its polymeric form, a feature Almutairi and her colleagues use to their advantage. After polymerizing the cresols, they cap each reactive component with a light-absorbing compound called Bhc. When the Bhcs absorb NIR light, the reactive groups are exposed and break the long polymer into two short chains. Shining additional light continues this breakdown, potentially releasing any drugs in the capsule. What's more, Almutairi says, Bhc is 10 times better at absorbing NIR than is ONB and is not poisonous to cells.
【小题1】According to the passage, which of the following could be the best trigger?