All the useful energy at the surface of the earth comes from the activity of the sun: The sun heats and feeds creatures and mankind. Each year it provides men with two hundred million tons of grain and nearly ten million tons of wood, coal, oil, natural gas, and all other fuels are stored energy from the sun. Some was collected by this season' s plants as carbon compounds. Some was stored by plants and trees ages ago. Even waterpower derives from the sun. Water turned into vapor by the sun fails as rain. It courses down the mountains and is converted to electric power. Light transmits only the energy that comes from the sun' s outer layer, and much of this energy that is directed towards the earth never arrives. About nine tenths of it is absorbed by the atmosphere of the earth. In fact, the earth itself gets only one half millionth of the sun' s entire output of radiant energy.
1.[单选题]Radiant energy is stored as carbon compounds by__________.
A.plants
B.water
C.rock
D.creatures
2.[单选题]The sun is the source of all of the following EXCEPT__________.
A.gasoline
B.natural gas
C.atomic power
D.animal fat
3.[单选题]Of the sun' s total output of radiant energy, the earth receives__________.
A.one tenth
B.one millionth
C.all that comes from the surface of the sun
D.a very small portion
4.[单选题]The largest part of the light energy directed towards the earth is__________.
A.stored up by the plants
B.absorbed by the earth' s atmosphere
C.stored up by the animals in the form of body fat
D.used for electric power
5.[单选题]The sun' s energy provides us with all EXCEPT__________.
A.rain
B.teal
C.water
D.light