[单项选择]Nearly (three quarters of the surface) of the earth (are) covered with water, and (there) would be even less land (if) the polar icecaps were melt.
A. three quarters of the surface
B. are
C. there
D. if

[单项选择]Nearly (three quarters) of the surface of the earth (are) covered with water, and there (would be) even less land (if) the polar icecaps were melted.
A. three quarters
B. are
C. would be
D. if

[单项选择]A body weighs _______ from the surface of the Earth.
A. less than it, the farther it gets
B. less the farther it gets
C. the farther it gets, the less
D. less than it gets farther

[单项选择]Light goes three quarters of the way from the earth to the noon in one second．
A. 光一秒钟以后能走完25%的路程、从地球到月球。
B. 光一秒钟可以走过地球至月球距离的75%。
C. 光一秒钟可以走过地球至月球距离的四分之三。
D. 光一秒钟可以通过地球到月球距离的四分之三。

[单项选择] Attempts have been made for nearly three decades to increase the amount of precipitation from clouds by seeding them with salt or silver iodide.
A. Devices
B. Hypotheses
C. Efforts
D. Suggestions

[单项选择](Alcoholics) have a death rate nearly three times more than (the general population); they are (seven times) more likely than non-alcoholics to (suffer) fatal accidents.
A. Alcoholics
B. the general population
C. seven times
D. suffer

[单项选择]______ have been made for nearly three decades to increase the amount of precipitation from clouds by seeding them with salt or silver iodide.
A. Devices
B. Hypotheses
C. Attempts
D. Commissions

[单项选择]For three quarters of its span on Earth, life evolved almost ______ as microorganisms.
A. precisely
B. instantly
C. initially
D. exclusively

[单项选择]

Passage Three All the useful energy at the surface of the earth comes from the activity of the sun. The sun heats and feeds 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-up energy from the sun. Some was collect ed 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 falls 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 layers, and much of this energy that is directed toward 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-billionth of the sun’ s entire output of radiant energy.

All the useful energy at the surface of the earth comes （）
A. directly from the sun
B. from the sun' s activity
C. from energy stored by the sun
D. from radiation of the sun