题目内容
（请给出正确答案）
Regeneration of a part of the body isimpossible without
A．general purpose cells．
B．bone cells．
C．muscle cells．
D．skin cells．
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更多“Regeneration of a part of the …”相关的问题
Regeneration of a part of the body isimpossible without
A．general purpose cells．
B．bone cells．
C．muscle cells．
D．skin cells
Regeneration of a part of the body is impossible without
A．general purpose cells.
B．bone cells.
C．muscle cells.
D．skin cells.
B、degeneration of the limb bud
C、regeneration of a new apical ridge from adjacent epidermal tissue
D、regeneration of the entire limb bud from underlying mesoderm
According to paragraph 2, what causes the Earth to remain the same size？
A．Constant regeneration of oceanic crust.
B．Earthquakes and volcanic eruptions.
C．The movement of divergent boundaries.
D．Interactions at transform. boundaries.
Regeneration of Limbs
Most people would agree that it would be wonderful if humans could regenerate limbs. These who have lost their arms or legs would be complete again. The day is still far off when this might happen. But in the last 10 years, doctors have reported regeneration in smaller parts of the body, most often fingers.
Regeneration is not a newly-discovered process. For centuries, scientists have seen it work in some kinds of animals. Break off a lizard's (蜥蜴的) tail, for example, and it will grow a new tail. Scientists now are looking for a way to turn on this exciting ability in more highly-developed animals, including humans. Their experiments show that nerves, cell chemistry and the natural electric currents in the body all seem to have a part in this process.
The body of every animal contains general purpose cells that change into whatever kind of cells the body needs. Animals such as the lizard or salamander (蝾螈) use these cells to regenerate a new tail or leg when the old one is broken off. These cells collect around the wound. They form. a mass called a blastama (胚基). The cells of the blastema begin to change. Some become bone cells, some muscle cells, some skin cells. Slowly, a new part regrows from the body outward. When completed, the new part is just like the old one.
Mote than 200 years ago, Italian scientist Luigi Spallanzani showed that younger animals have a greater ability to regenerate lost parts than older animals. So do animals lower on the ladder of evolutionary development. The major difference seems to be that less-developed animals have more nerves in their tails and legs than humans do in their arms and legs.
Another helpful piece of information was discovered in the late 1600s. Scientists found that when a creature is injured, an electrical current flows around the wound. The strength of the current depends on how severe the wound is and on how much nerve tissue is present.
In 1945, American scientist Meryl Rose tested another idea about regeneration. He thought a new limb might grow only from an open wound. Doctor Rose cut off the front legs of some frogs, below the knee. He kept the wounds wet with a strong salty liquid. This prevented skin from growing over the wounds. The results were surprising. Frogs do not regenerate new legs naturally. But these frogs began to grow new limbs. About half of each cut-off leg grew back again. New bones and muscles developed.
This research has led doctors to new ways of treating cut-off fingers. Doctors have observed, for example, that many children and some adults will regrow the top of a finger if the wound is left open.
The passage indicates that
A．humans can never regenerate limbs.
B．humans might be able to regenerate limbs in the future.
C．human limbs may be regenerated on some animals first.
D．regeneration of human limbs will soon become a reality.
根据下列文章,请回答 31～35 题。
Regeneration of Limbs
Most people would agree that it would bewonderful if humans could regenerate limbs．Those who have lost their arms orlegs would be complete again．The day is still far off when this might happen．Butin the last l o years，doctors have reported regeneration in smaller parts of the body,most often fingers．
Regeneration is not a newly-discoveredprocess．For centuries，scientists have seen it work in some kinds of animals．Breakoff a lizard's(蜥蜴的)tail，for example，and it will grow a new tail．Scientists noware looking for a way to turn on this exciting ability in more highly-developedanimals，including humans．Their experiments show that nerves，cell chemistry andthe natural electric currents in the body all seem to have a part in this process．
The body of every animal contains generalpurpose cells that change into whatever kind of cells the body needs．Animalssuch as the lizard or salamander(蝾螈)use these cells to regenerate a new tail．orleg when the old one is broken off．These cells collect around the wound．Theyform. a mass called a blastema(胚基)．The cells of the blastema begin to change．Somebecome bone cells，some muscle cells，some skin cells．Slowly，a new part regrowsfrom the body outward．When completed．the new part is just like the old one．
More than 2oo years a9o。Italian scientistLuigi Spallanzani showed that younger animals have a greater ability toregenerate lost parts than older animals。So do animals lower on the ladder ofevolutionary development．The major difference seems to be that less-developedanimals have more nerves in their tails and legs than humans do in their armsand legs．
Another helpful piece of information wasdiscovered in the late l 8oos．Scientists found that when a creature is injured．anelectrical current flows around the wound．The strength of the current dependson how severe the wound is and on how much nerve tissue is present．
In l 945，American scientist Meryl Rosetested another idea about regeneration．He thought a new limb might grow onlyfrom an open wound．Doctor Rose cut off the front legs of some frogs，below theknee．He kept the wounds wet with a strong salty liquid．This prevented skin fromgrowing over the wounds．The results were surprising．Frogs do not regenerate newlegs naturally．But these frogs began to grow new limbs．About half of eachcut—off leg grew back again．New bones and muscles developed．
This research has led doctors to new waysof treating cut-off fingers．Doctors have observed，for example，that manychildren and some adults will regrow the top of a finger if the wound is leftopen．
第 31 题 The passage indicates that
A．humans can never regenerate limbs．
B．humans might be able to regenerate limbsin the future．
C．human limbs may be regenerated on someanimals first．
D．regeneration of human limbs will SOON become a reality．
根据下面内容，回答题
A
The Birmingham Alliance will provide Birmingham with one of Europe"s largest regional shopping centres， right in the heart of the city．The Alliance， an initiative between three of the largest developers in the country， all with extensive experience of urban regeneration schemes， will facilitate an 800m investment in Birmingham．This will regenerate 40 acres of the city centre within the next decade．Planning permission is in place for the new scheme， which will be a short distance from existing prime retail areas．The development will be well serviced by all forms of public transport， as well as providing parking space forε 3，200 cars.
B
The private-public partnership between Legal & General and Bracknell Town Council will manage the ~ 500m regeneration of the town"s centre．The proposals， which are awaiting the outcome of consultation with local residents， provide for approximately 102，000 m2 of retail and leisure facilities， ε200 residential units and office accommodation．This development is expected to set the standard for town centre regeneration schemes to come because of the way it integrates the business and community sectors．It will also facilitate great improvements in the region"s transport infrastructure.
C
Bluewater is a symbol of retail excellence， achieved through a unique combination of design， retail mix， leisure， catering and hospitality．The centre， surrounded by parkland， is situated in the country"s most affluent region．Eleven million people， with a combined spending power predicted to exceed a record 5.5bn， live within 60 minutes of the centre．The developers set a precedent in the industry by gating the country"s three best-known department stores to open very large branches within the centre， as well as over 300 leading fashion and lifestyle. stores.
D
Following its recent stock market success， Lend Lease is now developing Overgate shopping centre in Dundee．Construction is well under way， and with several of the country"s best-known retailers already secured， Lend Lease is promoting the centre as the unrivalled shopping destination of the region．The economic base of the area has improved continuously over the past decade， due to the fast expansion of the biomedical and service sectors．With an estimated potential market of 500，000 people， Overgate is proving attractive to leading UK retailers.
This development is in an area where the potential for consumer spending is the highest in the country.
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