11.答案C

　　【解析】where引導地點狀語從句。

　　12.答案C

　　【解析】lodging and food“食宿”，固定搭配。

　　13.答案D

　　【解析】這里是說“學生可以受到居住地政府的資助，包括食宿，除非他父母富有。

　　14.答案B

　　【解析】這里是說大多數(shù)學生在暑假打工大約六星期。

　　15.答案D

　　【解析】在這里介詞for表示一段時間。

　　16.答案B

　　【解析】work與前面的jobs相呼應。

　　17.答案A

　　【解析】take responsibility for“對……承擔責任”，固定搭配。

　　18.答案C

　　【解析】這里是說教育部承擔了大學的全部支付。

　　19.答案C

　　【解析】have influence on“對……產(chǎn)生影響”，固定搭配。

　　20.答案B

　　【解析】be composed of“由……組成”，固定搭配。

　　Today, most countries in the world have canals.

　　Many countries have built canals near the coast, and parallel __1__ the coast.

　　Even in the twentieth century, goods can be moved more cheaply by boat than by any other __2__ of transport.

　　These __3__ make it possible for boats to travel __4__ ports along the coast without being __5__ to the dangers of the open.

　　Some canals, such as the Suez and the Panama, save ships weeks of time by making their __6__ a thousand miles shorter.

　　Other canals permit boats to reach cities that are not __7__ on the coast, still other canals __8__ landsswheresthere is too much water, help to __9__ fields wherethere is not enough water, and __10__ water power for factories and mills.

　　The size of a canal __11__ on the kind of boats going through it.

　　The canal must be wide enough to permit two of the largest boats using it to __12__ each other easily.

　　It must be deep enough to leave about two feet of water __13__ the keel of the largest boat using the canal.

　　When the planet Mars was first __14__ through a telescope, people saw that the round disk of the planet was criss-crossed by a __15__ of strange blue-green lines.

　　These were called“canals” __16__ they looked the same as canals on earth __17__ are viewed from an airplane.

　　However, scientists are now __18__ that the Martian phenomena are really not canals.

　　The photographs __19__ from space-ships have helped us to __20__ the truth about the Martia“canals”.

　　1.A.off B.with

　　C.to D.by