单选题 Imagine fishermen walking down to the seashore, ready to carry out their early morning routine of preparing their boats and net. (51) they hope for a good catch of fish. But to their (52) , a horrible sight meets their still sleepy eyes. Thousands of fish have been washed ashore dead. The cause of this mass destruction—A red tide!
Red tides are a global (53) . They have been observed on both the Atlantic and the Pacific coasts of the United States and Canada. They have also occurred in many other places. Though relatively few people are (54) 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 (55) . A Philippines red tide expert told us that " (56) the fish kills, the Philippines has documented 1, 926 eases of dead shellfish poisoning caused by red tides. "
The term "red tide" (57) 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 (58) of brown or yellow. The World Book Encyclopedia reports that "the discolored areas may range from (59) a few square yards to more than 2,600 square kilometers. "
What causes such discoloration? Red tides are generally caused by several species of single-celled organisms. These tiny organisms have hair-like projections which they use to (60) themselves in water.

单选题 A. As a result B. As it is C. As expected D. As usual

【正确答案】 D

【答案解析】[解析] A项表示“结果”；B项表示“实际上”；C项表示“正如所期待的”；D项表示“如往常一样”。根据前面句“routine”例行公事，常规，所以本句话应该表示的是一贯的动作，和往常一样。所以本题的正确答案为D。

单选题 A. satisfaction B. disappointment C. astonishment D. regret

【正确答案】 C

【答案解析】[解析] 根据文章后面一句提到的“恐怖的一幕”，联系各项与“to their”搭配表达的意思，A项“to their satisfaction”表示“令他们满意的是”；B项“to their disappointment”表示“令他们失望的是”；C项“to their astonishment”表示“令他们惊讶的是”；D项“to their regret”表示“令他们后悔的是”，可知最适合的选项是C。

单选题 A. question B. crisis C. phenomenon D. situation

【正确答案】 C

【答案解析】[解析] 这句话的意思大是说：赤潮是一个全球性的______。A项表示“问题，难题”；B项表示“危机，难关”；C项表示“现象，征兆”；D项表示“形势，状况”。因为赤潮是一种自然现象，本文解释了它形成的原因，所以应该选C。

单选题 A. assured of B. worried about C. concerned about D. aware of

【正确答案】 D

【答案解析】[解析] A项表示“被保证，被确保”，指告知……确实如此；B项表示“担心……”；C项表示“关心、关照……”；D项表示“知道、了解……”。后面的句子“red tides are not new'’是说赤潮并不是初为人知，可以推知前面一句话要表达的意思应该是有人知道，所以应该选D。

单选题 A. sandy beaches B. river mouths C. coastal areas D. reef areas

【正确答案】 C

【答案解析】[解析] 这里要填一个赤潮发生的具体地点。前面文章讲到过赤潮曾发生在美国和加拿大的大西洋和太平洋的沿岸，所以这里要选择一个相近的词。A项表示“沙质海滩”；B项表示“河口”；C项表示“海岸的，沿岸的”；D项表示“珊瑚礁区域”。所以应该选C。

单选题 A. except B. besides C. despite D. without

【正确答案】 B

【答案解析】[解析] 本句话前面讲到赤潮导致鱼死亡，接着讲赤潮使贝类中毒，可见这个关联词应该是“除了……之外，还有……”，A项表示“除……之外，除去”；B项表示“除……之外”，指除……外，另外还有……；C项表示“不论，尽管”；D项表示“没有，缺乏”。所以应该选B。

单选题 A. applies to B. sums up C. copes with D. leads to

【正确答案】 A

【答案解析】[解析] 这句话讲，“赤潮”这个术语有时用来表示发生在海或洋的某些区域的水变色。是在解释赤潮。A项表示“应用于，用来表示……”；B项表示“概括，总结”；C项表示“应付，对付”；D项表示“导致”。所以应该选A。

单选题 A. shadows B. shades C. shakes D. shapes

【正确答案】 B

【答案解析】[解析] 前一句已经指出“赤潮”这个术语有时用来表示发生在海或洋的某些区域的水变色。所以这里应该是水的颜色。A项表示“阴影，影子”；B项表示“色调，颜色”；C项表示“摇动，颤动”；D项表示“外形，形状”。所以应该选B。

单选题 A. less than B. more than C. as much as D. as little as

【正确答案】 A

【答案解析】[解析] A项表示“不到，少于”；B项表示“超过，多于”；C项表示“与……一样多”；D项表示“与……一样少”。根据句子中的“from…to”以及后面的“more than …”可知，这句话是一个对比，应与“more than…”所表达的意思相反，表示从小到大。所以应该选A。

单选题 A. propel B. probe C. proceed D. prompt

【正确答案】 A

【答案解析】[解析] A项表示“推动，推进”，指使……向前移动；B项表示“探查，查明”；C项表示“进行，着手”；D项表示“促使，怂恿”，指鼓舞……开始行动。文中讲到“这些生物利用……在水中前进”，所以应该选A。