The gravity on the earth is much ______ that on the moon, do you know why?

A．a(chǎn)s strong as

B．strong than

C．so strong than

D．stronger than

 

【答案】

D

【解析】略

 

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科目：高中英語 來源：必修三全優(yōu)指導(dǎo)北師英語 北師版 題型：050

閱讀理解

　　There are many problems connected with space travel．The first and greatest of them is gravity(重力)．If you let your pencil drop to the floor, you can see gravity in action．Everything is held to the earth by the force, which can be described by its weight．A rocket must go at least 2500 miles an hour to take anyone beyond the gravity of the earth into space．

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　　Once out of the earth’s gravity, an astronaut is affected by another problem, weightlessness．Here, if a pencil drops, it does not fall．If a glass of water is turned upside down, the water will not fall out．All of us are used to gravity．Recent long flights have shown that the body needs special exercise in a spaceship．

(1)

The weight is ________ the force gravity gives the object．

[　　]

A．

different from

B．

morn than

C．

less than

D．

as much as

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forward

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downward

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space travel

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problems in space travel

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gravity of the earth

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Space travel is definitely bad for astronauts’ bones, reducing their bone density(密度) after only a month of weightlessness, according to French research published on Friday.

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Space travel is definitely bad for astronauts’ bones, reducing their bone density(密度) after only a month of weightlessness, according to French research published on Friday.
Laurence Vico and his fellow workers at St Etienne University called for more research into the effects of microgravity, after their study of 15 astronauts from the Russian MIR station showed bone loss continued throughout space flights.
“Bone loss was especially striking in four astronauts, ” the scientists reported in the Lancet Medical Journal.
They measured the bone mineral density (BMD) of bones in the forearm(前臂) and lower leg of the astronauts who had spent one to six months in space.
The BMD loss was significant in the tibia(脛骨) of the lower leg, a weight-bearing bone, but barely changed in the radius(橈骨) of the forearm. “Our results indicate the need to investigate not only different bones, but also different areas of the same bone since not all sites of the skeleton (骨架) are similarly affected by space conditions, ” they added.
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The research team suggested in future scientists should try to determine if the loss of bone density was only on weight-bearing bones on longer flights, also the possible recovery after returning to Earth.
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A．they only cared for the Russian astronauts
B．they were not interested in their own astronauts
C．the Russian government invited them to do their research
D．the Russian astronauts worked in space for a long time
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A．the BMD loss may cause serious illness to astronauts
B．the BMD loss may cause some change in astronauts’ bodies
C．a(chǎn)stronauts shouldn’t care about the BMD loss
D．a(chǎn)stronauts should take some calcium before space travel
【小題3】 What cause the BMD loss to astronauts, according to this passage?
A．The food they eat in space.B．The drinks they take in space.
C．The temperature in space.D．The gravity in space.
【小題4】In the third paragraph, the word “striking” means ______.
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