[填空题]The output of coal in 1999 was _______________ (比 1972 年增加了五倍).

[填空题]The output of coal in 1999 was _______________ (比 1972 年增加了五倍).

[单项选择]Lincoln Coal is planning a new coal mine, which will cost $ 430000 to build, with the expenditure occurring next year. The mine will bring cash inflows of $ 200000 annually over next seven years. It will then cost $170000 to close down the mine over the following year. Assume all cash flows occur at the end of the year. Alternatively, Lincoln Coal may choose to sell the site today. What minimum price should Lincoln set on the property, given a 16% required rate of return

[单项选择]What is the recommended stock of coal
A. 115 tons.
B. 45 tons.
C. 70 tons.

[填空题]Geologists believe that oil and coal are composed of organic molecules______(因为它们本身来自于生物).

[单项选择]

Underground Coal Fires -- a Looming Catastrophe
Coal burning deep underground in China, India and Indonesia is threatening the environment and human life, scientists have warned. These large-scale underground blazes cause the ground temperature to heat up and kill surrounding vegetation, produce greenhouse gases and can even ignite forest fires, a panel of scientists told the annual meeting of the American Association for the Advancement of Science in Denver. The resulting release of poisonous elements like arsenic and mercury can also pollute local water sources and soils, they warned.
"Coal fires are a global catastrophe," said Associate Professor Glenn Stracher of East Georgia College in Swainsboro, USA. But surprisingly few people know about them.
Coal can heat up on its own, and eventually catch fire and burn, if there is a continuous oxygen supply. The heat produced is not caused to disappear and under the right combinations of sunli
A. Annual consumption of coal in US.
B. Annual consumption of coal in China.
C. How long coal fires has lasted in the northern region of China.
D. Coal fires can have an impact on the environment.

[填空题]The factories and coal mines in Upper Silesia produced much more pollution than Ruhr Valley in Germany.

[单项选择]Underground Coal Fires -- a Looming Catastrophe
Coal burning deep underground in China, India and Indonesia is threatening the environment and human life, scientists have warned. These large-scale underground blazes cause the ground temperature to heat up and kill surrounding vegetation, produce greenhouse gases and can even ignite forest fires, a panel of scientists told the annual meeting of the American Association for the Advancement of Science in Denver. The resulting release of poisonous elements like arsenic and mercury can also pollute local water sources and soils, they warned.
"Coal fires are a global catastrophe," said Associate Professor Glenn Stracher of East Georgia College in Swainsboro, USA. But surprisingly few people know about them.
Coal can heat up on its own, and eventually catch fire and burn, if there is a continuous oxygen supply. The heat produced is not caused to disappear and under the right combinations of sunlight and oxygen, can trigg
A. underground fires loom large in the forests.
B. coal burning deep underground is found in China.
C. poisonous elements released by the underground fires can pollute water sources.
D. arsenic and mercury are the most poisonous elements to water sources.

[单项选择]According to news, the West Virginia coal mine disaster
A. caused minor injuries.
B. was the worst one since 1984.
C. was caused by terrorist attack.
D. happened in early morning.

[单项选择]Which of the following is a disadvantage of coal fires（）
A. It is rather expensive.
B. It cannot provide enough hot water.
C. It cannot be used for heating the living room.
D. It produces a lot of work and dust.

[简答题]Coal and oil which have been regarded as the chief resources in our daily life will soon be replaced by solar energy in the near future.