[单项选择]

(五)

Space travel is definitely bad for astronauts’ bones, reducing their bone density 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 and lower leg of the astronauts who had spent one to six months in space.
The BMD loss was significant in the tibia of the lower leg, a weight-bearing bone, but barely changed in the radius 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
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

[单项选择]
Space travel is definitely bad for astronauts’ bones, reducing their bone density 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 and lower leg of the astronauts who had spent one to six months in space.
The BMD loss was significant in the tibia of the lower leg, a weight-bearing bone, but barely changed in the radius 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
A. the BMD loss may cause serious illness to astronauts
B. the BMI) loss may cause some change in astronauts’ bodies
C. astronauts shouldn’t care about the BMD loss
D. astronauts should take some calcium before space travel

[单项选择]Space travel is definitely bad for astronauts’ bones, reducing their bone density 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 and lower leg of the astronauts who had spent one to six months in space.
The BMD loss was significant in the tibia of the lower leg, a weight-bearing bone, but barely changed in the radius 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 are similarly affected by space con
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

[单项选择] Space Travel in the Future Space flight may be about to undergo a transformation far more radical than anything planned by national or international space agencies. In the next fifteen years or so , there could be a fleet of fifty space-planes carrying a million people into orbit about the Earth each year, at $ 10,000 per head. A prototype of spaceplane could be up and flying within five or six years. Perhaps surprisingly the main obstacles to realizing this dream are neither technical nor commercial. Space transportation is expensive and risky at present because all launchers so far have used large throw-away components that are based on ballistic missile technology. But the technology already exists for a prototype of a fully reusable, aeroplane-like launcher, and its development costs need only be equivalent to about two space shuttle flights (about $ 1,000 million). The cost per prototype space-plane flight would be about 1 percent of the cost in t
A. Y
B. N
C. NG

[填空题]
Between 1977 and 1981, three groups of American women, numbering 27 in all, between the age of 35 and 65, were given month-long tests for space travel purposes. (46) .
Those women were carefully selected from among many applicants. (47) . They were not allowed to smoke or drink alcohol during the tests, and they were expected to tolerate each other’s company at close quarters for the entire period. Among other things they had to stand pressure three times the force of gravity and carry out both physical and mental tasks while exhausted from strenuous physical exercise. (48) . During that time they suffered backaches and other discomforts. (49) .
Results of the tests suggest that women will have significant advantages over men m space. (50) . Men’s advantages in terms of strength and stamina, meanwhile, are virtually wiped out by the zero-gravity con