单选题 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.

单选题 The sun is the source of all of the following EXCEPT ______.

【正确答案】 C

【答案解析】[解析] 第二、三句：“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 ale stored energy from the sun. ”
事实细节题。根据定位句可知，地球上的一切动植物、人类、树木、煤矿、石油、天然气、其他燃料等能量都来源于太阳，未提及原子能。故选C。

单选题 Radiant energy is stored as carbon compounds by ______.

【正确答案】 A

【答案解析】[解析] 第四句：“Some was collected by this season"s plants as carbon compounds. ”
事实细节题。根据定位句可知，植物体内储存着作为太阳能的碳的化合物。故选A。

单选题 The sun"s energy provides us with all EXCEPT ______.

【正确答案】 B

【答案解析】[解析] 第七句：“Water turned into vapor by the sun fails as rain. ”第九句：“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. ”
事实细节题。根据定位句可知，水能、雨水和光都来自于太阳能。B项表示“水鸭”，文中未提及。故选B。

单选题 The largest part of the light energy directed towards the earth is ______.

【正确答案】 B

【答案解析】[解析] 第十句：“About nine tenths of it is absorbed by the atmosphere of the earth. ”
事实细节题。根据定位句可知，9/10的能量被地球的大气层吸收了。故选B。

单选题 Of the sun"s total output of radiant energy, the earth receives ______.

【正确答案】 D

【答案解析】[解析] 最后一句：“In fact, the earth itself gets only one half millionth of the sun"s entire output of radiant energy. ”
推理判断题。根据定位句可知，事实上，地球本身只能得到1/500000的全部太阳光能量。所以是相当小的一个比例。故选D。