单项选择题

Fish resources are diminishing because ______.

A．no new substitutes can be found in large quantities
B．they are not owned by any particular entity(实体)
C．improper methods of fishing have ruined the fishing grounds
D．water pollution is extremely serious

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热门试题

单项选择题

The main function of the shell is ______.

A．to strengthen the pilings of the house
B．to give the house a better appearance
C．to protect the wooden frame of the house
D．to slow down the speed of the swelling water

单项选择题

Alter the tragedy mused by Hurricane Hugo, new houses built along South Carolina's shore line are required ______.

A．to be easily reinforced
B．to look smarter in design
C．to meet stricter building standards
D．to be designed in the shape of cubes