那达慕大会是哪个民族的节日( ) A . 苗族 B . 傣族 C . 朝鲜族 D . 蒙古族 答案:D4、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.”
67.Babies 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 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
68.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
69.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
70.The underlined word “vulnerable” in the passage probably means __________.
A.easy to be harmed
B.resistant
C.protective
D.changeable
评卷人
得分
二、信息匹配
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