The problem of underground water is more serious because( )
[A] the underground water trickles away all the year round
[B] the underground water is hidden deep beneath the Earth
[C] the change of it must be controlled by the NASA's satellites
[D] the dramatic change of it might affect the gravitational field
第1题:
B
The world is not only hungry,it is also thirsty for water. this may seem strange to you,since nearly 75% of the earth is covered with water. But about 97% of this water is sea water.Man can only drink and use the other 3% fresh water that comes from rivers,lakes,under-ground and other places. And we cannot even use all of that,because some of this fresh water has been made dirty.
At the moment,this small amount(数量) of fresh water is still enough for us. However,our need for water is getting greater and greater. Only if we take steps to solve this problem now,we can get away from a serious world water shortage later on. The people of the world cannot have an enjoyable life without enough clean water.
On one hand we should stop wasting this little water of ours,on the other hand we should find ways to reuse it,but this has not been done widely.
Today,in most large cities,water is used only once and it then returns to the sea or runs into underground places.lf we can make it clean again,it can be used once more just as if it were fresh from a spring.
But even if large cities reuse its water,we still would not have enough in the future. Where.could we turn to next for water? To the ocean! How can we do to make use of this great a-mount of sea water? We can take the salt from the water to make it fresh.
So if we take all these steps,we'll be in no danger of drying up!
( )26. Why does the writer say that the world is thirsty for water?
A. The amount of fresh water is really very small.
B. The people of the world waste too much water.
C. The people of the world have to drink a lot of water every day.
D. There are too many people in the world needing water.
第2题:
第3题:
第4题:
第5题:
第6题:
地道 underground path
第7题:
VHF communications are basically line of sight
the air is more dense the higher you go
salt water is a poor conductor of sound
sea water absorbs the radiated energy
第8题:
第9题:
第10题:
like
as
of
about
第11题:
people should not take street level transportation
tiny iron particles will not cause health problems
air pollution on an underground train is less poisonous
traveling on an underground train is better than taking the bus
第12题:
Some are built underground.
Some can be eaten.
Most are sewed with grasses.
Most are dried by the sun.
第13题:
Underground-economy 地下经济
未报告的经济活动。地下经济包括本属合法,但未向税收机关报告的活动[如现场旧货出售(garage
sale)或亲朋间提供的服务]和非法活动(如贩毒、赌博和卖淫)。
第14题:
第15题:
第16题:
第17题:
Such problem ()air, water, and noise pollutions are becoming more and more serious in some big cities.
Alike
Bas
Cof
Dabout
第18题:
第19题:
absorb
relieve
withdraw
suck
第20题:
we not need
not necessary for us
it being unnecessary
it is not necessary for us
第21题:
has been exaggerated by some experts in the field
is underestimated by government organizations at different levels
poses a challenge to the technology of building reservoirs
is already serious in certain parts of the world
第22题:
第23题: