Today, most countries in the world have canals. Many countries have built canals near the coast, and parallel【C1】______the coast

admin2017-06-30  32

问题     Today, most countries in the world have canals. Many countries have built canals near the coast, and parallel【C1】______the coast. Even in the twentieth century, goods can be moved more cheaply by boat than by any other means of transport. These【C2】______make it possible for boats to travel between ports along the coast without being【C3】______to the dangers of the open. Some canals, such as the Suez and the Panama, save ships weeks of time by making their voyage a thousand miles shorter. Other canals permit boats to reach cities that are not【C4】______on the coast, still other canals drain lands where there is too much water, help to【C5】______fields where there is not enough water, and furnish water power for factories and mills. The size of a canal【C6】______on the kind of boats going through it. The canal must be wide enough to permit two of the largest boats using it to pass each other easily. It must be deep enough to leave about two feet of water【C7】______the keel of the largest boat using the canal. When the planet Mars was first observed through a telescope, people saw that the round disk of the planet was crisscrossed by a【C8】______of strange blue-green lines. These were called "canals" because they looked the same as canals on earth【C9】______are viewed from an airplane. However, scientists are now certain that the Martian phenomena are really not canals. The photographs【C10】______from space-ships have helped us to discover the truth about the Martia"canals".
【C9】

选项 A、that
B、where
C、when
D、as

答案A

解析
转载请注明原文地址:https://jikaoti.com/ti/QgBfFFFM
0

最新回复(0)