2.Some persons have traveled into outer space afte［A］the universe［B］Earth’s gravity［C］the earth［D］outer space

Much__________I have traveled, I have never seen anyone to equal her in efficiency.

A．although
B．as
C．while
D．if

共用题干
Motion Sickness

Living in space looks like lots of fun.You can do certain things in space(like floating
around,or pushing huge objects)that you cannot do on earth.But being in space can do
things to you,too.If you stay too long in a gravity-free environment,your bones could
become weak,and a small spaceship just might annoy you after a while,because space
travel could make you seasick!
On July 4, 1982,after seven days orbiting the earth,astronauts Thomas K. Mattingly
and Henry W. Hartsfield returned home.Although not all of the experiments on board
worked properly,the flight basically seemed to be a success except for one"little"thing:
early in the flight,astronaut Hartsfield became"seasick".
Thomas Mattingly,who is also a jet pilot and is highly resistant to motion sickness on
earth,did much better.Mattingly sailed through space with a steady stomach.But no one
knows why Hartsfield felt uneasy and Mattingly did not.
So far it seems there is no reliable way to predict who will become motion sick in
outer space and who will not.In all,at least four astronauts have suffered from space
motion sickness. Russian and American scientists are working together to try to
understand and solve the motion sickness.Space program officials worry that if so
many highly-trained pilots get sick in space,what will happen when civilians start flying
in the shuttle?
Motion sickness is a disagreeable feeling that comes from the pitching,rolling,
swaying,or just the moving of the object you are riding in or on.Symptoms of motion
sickness include:dizziness,headache,a sinking feeling in the stomach,and vomiting
（呕吐）.
Why does motion make some people ill?
Doctors believe that motion sickness is caused by a disturbance in the inner ear.Our
ears do more than give us hearing.A part of the ears gives us a sense of balance and helps
make us aware of whether we are right side up or upside down.
If you know that you get carsick or seasick,what can you do?
Speak to your doctor. There are certain medicines available that can help stop that
uneasy feeling.But many of them can also make you sleepy.Usually they work best taken
before you begin feeling ill.
Some people also recommend water,ice cubes,mints,or plain toast.But these
remedies do not always work for everyone.
Perhaps,since motion sickness is such a big problem in outer space,researchers
may soon find a way to cure the astronauts一and those of us who stay on earth.

Mattingly was much thinner than Hartsfield.
A:Right
B:Wrong
C:Not mentioned

Space is a dangerous place,not only because of meteors but also because of rays from the sun?and other stars.The atmosphere again acts as our protective blanket on earth.Light gets through,and?this is essential for plants to make the food which we eat.Heat,too,makes our environment endurable.Various kinds of rays come through the air from outer space,but enormous quantities of radiation from the sun are screened off.As soon as men leave the atmosphere they are exposed to this radiation.But their spacesuits or the walls of their spacecraft,if they are inside,do prevent a lot of radiation damage.
Radiation is the greatest known danger to explorers in space.The unit of radiation is called"rein".Scientists have reason to think that a man can put up with far more radiation than 0.1 rem?without being damaged;the figure of 60 rems has been agreed on.The trouble is that it is extremely?difficult to be sure about radiation damage—a person may feel perfectly well,but the cells of his or?her sex organs may be damaged,and this will not be discovered until the birth of deformed(畸形的)children or even grandchildren.Missions of the Apollo flights have had to cross belts of high radiation?and,during the outward and return journeys,the Apollo crew accumulated a large amount of rems.So?far,no dangerous amounts of radiation have been reported,but the Apollo missions have been quite?short.We simply do not know yet how men are going to get on when they spend weeks and months?outside the protection of the atmosphere,working in a space laboratory.Drugs might help to decrease?the damage done by radiation,but no really effective ones have been found so far.

It can be inferred from the passage that__

A.the Apollo mission was very successful
B.protection from space radiation is no easy job
C.astronauts will have deformed children or grandchildren
D.radiation is not a threat to well-protected space explorers

共用题干
Where Did the Earth's Water Come From?

Earth is located within the"snow line"of the solar system,the region closest to the Sun where H2 0 is primarily in liquid or gaseous form,if at all.______(46)The snow line phenomena is reflected in the water content of planets like Mercury,Venus,and Mars. Water is absent on Mercury.On Venus,H₂O only exists as a trace element in the atmosphere.Mars only has a thin veneer of ice in its polar regions.In general,water is rare within the snow line.
Why does Earth have so much water relative to the other inner planets?71%of the surface is covered in the oceans,more than half of which is deeper than 3,000 meters,with an approximate total volume of 1.3 billion cu km.______(47)
There are various theories as to where all the Earth's water came from,but several theories have fared better than the others.______(48)When the Earth was in the process of forming,with a radius just 40%smaller than at present,it would have had enough gravity to hold on to a tenuous atmosphere with water vapor. The first water vapor on the planet would have come from the planet's internals,where volatile(low weight)chemicals would have a tendency to float to the top,and heavy chemicals(iron and nickel)would sink.
Though the first of Earth's water came about through volcanism,this alone probably didn't produce enough to form stable pools on the surface.______(49)Comparing the isotope ratios of water on Earth and water from comets and asteroids has revealed that the majority of the Earth's water comes from asteroids.
Throughout its history,Earth's water has increased in volume due to biological processes. In the early seas of Earth,hydrogen sulfide would have been in great supply,which,when reacted with carbon dioxide from the atmosphere during photosynthesis in sulfide-reducing bacteria,would have produced hydrogen,sulfur,and water.______(50)

________（49）
A: More water was added to the planet during several hypothesized large impacts from asteroids from the outer asteroid belt.
B:We know that the oceans existed as early as 100 million years after the formation of the Earth.
C:Still,the oceans only make up 0.023%of the Earth's total mass.
D:Astronomers say Earth s water may have come from space.
E:The snow line is located in the outerasteroid belt,between the orbits of Mars and Jupiter.
F: Many geologists believe that the majority of Earth's water generated through this process.

Much __________I have traveled, I have never seen anyone to equal her in efficiency．

A.although
B.as
C.while
D.if

Much __________ I have traveled, I have never seen anyone to equal her in efficiency.

A.although
B.as
C.while
D.if

共用题干
Motion Sickness

Living in space looks like lots of fun.You can do certain things in space(like floating
around,or pushing huge objects)that you cannot do on earth.But being in space can do
things to you,too.If you stay too long in a gravity-free environment,your bones could
become weak,and a small spaceship just might annoy you after a while,because space
travel could make you seasick!
On July 4, 1982,after seven days orbiting the earth,astronauts Thomas K. Mattingly
and Henry W. Hartsfield returned home.Although not all of the experiments on board
worked properly,the flight basically seemed to be a success except for one"little"thing:
early in the flight,astronaut Hartsfield became"seasick".
Thomas Mattingly,who is also a jet pilot and is highly resistant to motion sickness on
earth,did much better.Mattingly sailed through space with a steady stomach.But no one
knows why Hartsfield felt uneasy and Mattingly did not.
So far it seems there is no reliable way to predict who will become motion sick in
outer space and who will not.In all,at least four astronauts have suffered from space
motion sickness. Russian and American scientists are working together to try to
understand and solve the motion sickness.Space program officials worry that if so
many highly-trained pilots get sick in space,what will happen when civilians start flying
in the shuttle?
Motion sickness is a disagreeable feeling that comes from the pitching,rolling,
swaying,or just the moving of the object you are riding in or on.Symptoms of motion
sickness include:dizziness,headache,a sinking feeling in the stomach,and vomiting
（呕吐）.
Why does motion make some people ill?
Doctors believe that motion sickness is caused by a disturbance in the inner ear.Our
ears do more than give us hearing.A part of the ears gives us a sense of balance and helps
make us aware of whether we are right side up or upside down.
If you know that you get carsick or seasick,what can you do?
Speak to your doctor. There are certain medicines available that can help stop that
uneasy feeling.But many of them can also make you sleepy.Usually they work best taken
before you begin feeling ill.
Some people also recommend water,ice cubes,mints,or plain toast.But these
remedies do not always work for everyone.
Perhaps,since motion sickness is such a big problem in outer space,researchers
may soon find a way to cure the astronauts一and those of us who stay on earth.

Floating in space for too long a time may also do harm to one's lungs and heart.
A:Right
B:Wrong
C:Not mentioned

Space is a dangerous place,not only because of meteors but also because of rays from the sun?and other stars.The atmosphere again acts as our protective blanket on earth.Light gets through,and?this is essential for plants to make the food which we eat.Heat,too,makes our environment endurable.Various kinds of rays come through the air from outer space,but enormous quantities of radiation from the sun are screened off.As soon as men leave the atmosphere they are exposed to this radiation.But their spacesuits or the walls of their spacecraft,if they are inside,do prevent a lot of radiation damage.
Radiation is the greatest known danger to explorers in space.The unit of radiation is called"rein".Scientists have reason to think that a man can put up with far more radiation than 0.1 rem?without being damaged;the figure of 60 rems has been agreed on.The trouble is that it is extremely?difficult to be sure about radiation damage—a person may feel perfectly well,but the cells of his or?her sex organs may be damaged,and this will not be discovered until the birth of deformed(畸形的)children or even grandchildren.Missions of the Apollo flights have had to cross belts of high radiation?and,during the outward and return journeys,the Apollo crew accumulated a large amount of rems.So?far,no dangerous amounts of radiation have been reported,but the Apollo missions have been quite?short.We simply do not know yet how men are going to get on when they spend weeks and months?outside the protection of the atmosphere,working in a space laboratory.Drugs might help to decrease?the damage done by radiation,but no really effective ones have been found so far.

The best title for this passage would be__

A.The Atmosphere and Our Environment
B.Research on Radiation
C.Effects of Space Radiation
D.Importance of Protection Against Radiation