首页
登录
职称英语
What produces a waterproof super glue, acts like a vacuum cleaner, and even
What produces a waterproof super glue, acts like a vacuum cleaner, and even
游客
2024-06-02
14
管理
问题
What produces a waterproof super glue, acts like a vacuum cleaner, and even teaches scientists about gene repair? The humble little shellfish known as the mussel (贻贝).
Mussels are found worldwide. Some live in the sea. Others inhabit freshwater streams and lakes. When you try to move a mussel from a rock, you will discover what an incredibly firm grip it has-a necessity if the mussel is to resist the sharp grab of a hungry seabird or the pounding waves of the sea. How does it manage to cling so tight’? When it chooses a place to set up home, it pokes its tongue-shaped foot out of its shell and presses it against a solid surface. Special glands give off a fluid mixture of proteins into a channel that runs the length of the foot. The liquid quickly hardens into a fine, elastic thread about an inch long. Then a tiny pad-like structure at the end of this thread gives off some natural glue-like substance, the mussel lifts its foot, and anchor line number one is complete. These strategically placed threads form a bundle, which ties the mussel to its new home in much the same way that ropes hold down a tent. The whole procedure takes only three or four minutes.
Imagine having a very strong glue that is non-toxic and so flexible that it can penetrate the tiniest holes and comers, sticking to any surface, even under water. Shipbuilders would welcome it for repairing vessels without the expense of dry-docking them. Auto-body workers would like a really waterproof paint that keeps the rust out. Surgeons would value a safe glue to join broken bones and to close wounds... The list of possible uses appears endless.
However, scientists are not thinking of using the mussels themselves to produce this super glue. It would take some 10 000 shellfish to make just one gram of glue. So collecting enough mussels to supply the world’s demand for super glue would wipe out the mussel population, many species of which are already endangered. Instead, American researchers have isolated and cloned the genes for five mussel glue proteins, and they are about to mass-produce them in the laboratory. However, the mussel is still one jump ahead. Only the mussel instinctively knows the exact blend of proteins needed for each kind of surface. Molecular biologist Frank Roberto has asked admiringly:" how are you ever going to imitate that?" [br] A mussel grips a hard surface very firmly to ______.
选项
A、seal itself from being eroded by sea water
B、produce the waterproof super glue
C、protect itself from being blown away by strong wind
D、protect itself from being the food of other animals
答案
D
解析
细节题。注意此句破折号后面的解释:要防止"hungry seabird"和"pounding waves",故答案为D项。
转载请注明原文地址:https://tihaiku.com/zcyy/3616560.html
相关试题推荐
Whatproducesawaterproofsuperglue,actslikeavacuumcleaner,andeven
Whatproducesawaterproofsuperglue,actslikeavacuumcleaner,andeven
Whatproducesawaterproofsuperglue,actslikeavacuumcleaner,andeven
Whatproducesawaterproofsuperglue,actslikeavacuumcleaner,andeven
Whatproducesawaterproofsuperglue,actslikeavacuumcleaner,andeven
Thecustomerisstill______aboutthefunctionsofthevacuumcleanerinspite
Collegestudentsinthiscityhavesetup"theCleanerAirSociety"tohelpurba
随机试题
A、Ithaslastedfornearly350years.B、Ithaslastedformorethan350months.
EmployeesintheUSarepaidfortheirtime.Thismeansthattheyaresupposedt
Scientistshavelearnedmoreaboutthewaycancerspreadsfromoneplacein
江苏省无锡市某中学张老师一走进教室,就发现那只很脏的痰盂,仍然挑战似地摆在教室的
振动法索力测试中,索力计算无须考虑的参数是()。A:索横向自振频率 B:索的
李女士,35岁,孕2产1,平素月经规律,经期无不适。近4个月阴道分泌物增多伴外阴
220kV及以下套管新设备投运前油中溶解气体含量乙炔小于()μL/L。(A)0.
在经济周期的过热阶段,对应的最佳的选择是( )资产。A.现金 B.债券 C
心理咨询师说:“如果你能……或许就会更好。”这句话使用了()。 A.情感表达技
计数标准型二次抽样检验方案为(N,n1,n2,C1,C2),N为送检批的大小,在
最新回复
(
0
)