题目内容
The word "centenary" (Paragraph 4, Line 3 ) most probably means ______.
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According to the conversation, what is the cost for each person in such a luxury room each
听力原文： Good morning. This morning we are continuing our look at Australia and its natural problems. Australia is a dry continent, second only to Antarctica in its lack of rainfall. Long hours of hot sunshine and searing winds give Australia an extremely high rate of evaporation, for more than in most other countries. It is estimated that approximately 87% of Australia's rainfall is lost through evaporation, compared with just over 60% in Europe and Africa and 48 % in North America.
Remarkably, underground water sources in Australia supply about 18% of total water consumption. So you can see it is quite an important source of water in this dry land.
So most of the consumption of water in Australia comes form. water which is kept above ground. More than 300 dams regulate river flows around the country. The dams store water for a variety of functions, the rural irrigation of crops, without which many productive areas of the country would not be able to be farmed; the regulation of flooding, a serious problem which will be dealt with later in the course; and last but not least, the harnessing of the force of gravity for the generation of electricity.
The driest continents is______.
Space is filled with radiant energy and beyond earth's atmosphere this energy flow steadily and intensely from the sun. An abundant and essential【C1】______of energy would be used in space by developing satellite solar【C2】______stations. To live in space, humans must be protected【C3】______the fierce intensity and penetrating sunlight. The colony will have to have enough energy to【C4】______a fairly uniform. temperature. The sun is not dimmed【C5】______an atmosphere. Shaded materials not【C6】______to direct sunlight will almost be absolute zero, while the temperature can soar above the【C7】______point. The colony will need to have both heaters and【C8】______Fortunately, sun's energy can be converted【C9】______electricity. Converting sun's energy, we would【C10】______stations in the space that would intercept【C11】______sunlight. The stations intercept enough sunlight to【C12】______five nuclear reactors and they could be as【C13】______as nine miles long and four miles wide while they weigh twenty thousand tons. This is a【C14】______free way to generate electricity and cost no【C15】______than coal or nuclear energy. Solar cells do the actual converting. A useful material found in lunar soil is silicon which is used to make solar cells.【C16】______we can produce a large amount of these cells and then we avoid any problems of【C17】______the material from earth. A solar cell is made from two thin layers of silicon. Sunlight【C18】______on the cell shakes the electrons【C19】______, and then these electrons move off into an outside circuit, which is detected as an electrical current. Things are arranged【C20】______most of the work involved in generating the electricity is done by forces associated with the atoms themselves.
【C1】
As is explained in the passage, snapshots refer to ______.
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