Imagine fishermen walking down to the seashore, ready to carry out their early morning routine of preparing their boats and net.

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问题     Imagine fishermen walking down to the seashore, ready to carry out their early morning routine of preparing their boats and net.【C1】______they hope for a good catch of fish. But to their 【C2】______, a horrible sight meets their still sleepy eyes. Thousands of fish have been washed【C3】______dead. The cause of this mass destruction? A red tide!
    Red tides are a global【C4】______. They have been observed on both the Atlantic and the Pacific coasts of the United States and Canada. They have also【C5】______in many other places. Though relatively few people are【C6】______them, red tides are not new.
    In the Philippines, a red tide was first seen in the province of Bataan in 1908. Since then, red tides have been seen in many other【C7】______. A Philippines red tide expert told us that "【C8】______the fish kills, the Philippines has documented 1, 926 cases of dead shellfish poisoning caused by red tides. "
    The term "red tide"【C9】______the discoloration of water that sometimes occurs in certain areas of the ocean or sea. Although the color is often red, it may also be【C10】______of brown or yellow. The World Book Encyclopedia reports that "the discolored areas may range from【C11】______a few square yards to more than 2,600 square kilometers. "
    What causes such discoloration? Red tides are generally caused by several【C12】______of single-celled organisms. These tiny organisms have hair-like projections which they use to【C13】______themselves in water. There are about 2,000 varieties of these organisms, 30 of which carry poisonous【C14】______. These minute organisms usually stay in warm waters with high content of salt.
    A red tide occurs when there is a sudden and rapid【C15】______of these organisms. The concentration of these organisms may【C16】______to 50,000,000 per quart of water! Although scientists do not fully understand why this happens, it is known that these organisms【C17】______when certain conditions simultaneously affect the water. These include abnormal weather, 【C18】______temperatures, an oversupply of nutrients in the water, a generous【C19】______sunlight, and favorable water currents. When a heavy rainfall occurs, minerals and other nutrients are sometimes washed【C20】______the land into coastal water. These nutrients can contribute to the breeding of the organisms. The result? Red tides!
【C17】

选项 A、accelerate
B、accommodate
C、accumulate
D、accompany

答案C

解析
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