题目内容
阅读理解：
The sea world is divided into three main oceans, the Pacific, the Atlantic and the Indian and two smaller oceans, the Arctic or the Northern Ocean, and the Antarctic or the Southern Ocean. The Pacific is by far the largest of these, for it covers half the sea- area of the world. In addition to the oceans there are other areas of sea, such as the Red Sea, the Mediterranean, the North Sea, the Caribbean Sea (加勒比海) and the Black Sea.
The continents are entirely surrounded by what is called the “continental shelf” which slopes (倾斜) gradually to a depth of about 500 feet. This shelf is built up of sediment (沉积物) which has been brought down to the sea by the continental river. Where the land near the coast is low and flat, the continental shelf may extend thirty, forty or even more miles from the coast; where mountain ranges run parallel (平行的) to the sea and near to it ( as on the east coast of Africa), the shelf is narrowed to only a mile or two.
From the edge of the shelf the sea- bed slopes sharply downwards so that the depth of water from the surface rapidly becomes greater, down to perhaps 1,200 feet.
1．Choose a correct diagram (示意图) from the following according to the information given:
[ ]
A．
B．
C．
D．
2．Which of those is the biggest?
[ ]
3．The continental shelf is found ________.
[ ]
4．The greatest area of continental shelf is to be found ________.
[ ]
A．at a depth of 500 feet
B．near low, flat coastline
C．near mountain ranges paralleled to the sea
D．off the east coast of Africa
5．The depth of the continental shelf varies (不同，不等) from ________.
[ ]
解析：
|
|
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||||||||||||||||