2012年大学英语四级<完形填空>模拟试题21

2012年大学英语四级<完形填空>模拟试题21

Directions: There are 20 blanks in the following passage. For each blank there are four choices marked [A] [B], [ C ] and [D ] on the right side of the paper. You should choose the ONE that best tits into the passage. Then mark the corresponding letter on Answer Sheet 2 with a single line through the centre.
　　注意：此部分试题请在答题卡2 L作答。
　　Today, most countries in the world have canals. Many countries have built canals near the coast, and parallel 67 the coast. Even in the twentieth century, goods can be moved more cheaply by boat than by any other _68_ of transport. 考试用书
　　These _69 make it possible for boats to travel __7 0_ ports along the coast without being _7_1_ to the dangers of the open. Some canals, such as the Suez and the Panama, save ships weeks of time by making their 72 a thousand miles shorter. Other canals permit boats to reach cities that are not 73 on the coast; still other canals .74._ lands where there is too much water, help to _75 fields where there is not enough water, and 76_. water power for factories and mills. The size of a canal ___7_7_ on the kind of boats going through it. The canal must be wide enough to permit two of the largest boats using it to _7_8 each other easily. It must be deep enough to leave about two feet of water .79__ the keel of the largest boat using the canal. When the planet Mars was first ._80_ through a telescope, people saw that the round disk of the planet was crises-crossed by a 8l of strange blue- green lines. These were called "canals" _82_ they looked the same as canals on earth 83 are viewed from an airplane.
　　However, scientists are now 84 that the Martian phenomena are really not canals. The photographs ~ 85 from space-ships have helped us to __86~ the truth about the Martian "canals".