Even in fresh water sharks hunt and
kill. The Thresher shark, capable of lifting a small boat out of the water, has
been sighted a mile inland on the Fowey River in Corn-wall. Killer sharks swim
rivers to reach Lake Nicaragua in Central America; they average one human victim
each year. Sewage and garbage attract sharks inland. When floods carry garbage to the rivers they provide a rich diet which sometimes stimulates an epidemic of shark attacks. Warm water generally provides shark food, and a rich diet inflames the shark’s aggression. In British waters sharks usually swim peacefully between ten and twenty miles off- shore where warm water currents fatten mackerel and pilchards for their food. But the shark is terrifyingly unpredictable. One seaman was severely mauled as far north as Wick in Scotland. Small boats have been att A. salt water B. fresh water C. warm water D. deep water [填空题]What percentage does the fresh water account for
Only () percent. [单项选择]Glaciers are a possible source of fresh water that has been overlooked until recently. Three quarters of the Earth’s fresh water supply is still tied up in glacial ice, a reservoir of untapped fresh water so immense that it could sustain all the rivers of the world for 1,000 years. Floating on the oceans are 7,659 trillion metric tons of ice encased in 10,000 icebergs that break away from the polar ice caps, more than ninety percent of them from Antarctic
A. How much fresh water is tied up in glacial ice 75 % of the Earth’s fresh water supply.B. 90% of the Earth’s fresh water supply.C. Enough to support human beings for 1,000 years.D. As much as the water from 10,000 trillion metric tons of ic [填空题]One solution to fresh water shortage is to to use drip irrigation.
[填空题]Why people can’t use all of the fresh water
Because some of it is(). 我来回答: 提交
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