单项选择题

In the author's opinion ,point-source pollution is ______.

A．less difficult to control than non-point pollution
B．the minor pollution source
C．more difficult to control than non-point pollution
D．a problem that cannot be solved

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热门试题

单项选择题

We can infer from tile passage that ______.

A．voodoo prevails more in Africa than in other pans of the world
B．the sudden deaths of animals differ in causes from those of people
C．the connection between sympathetic nervous system and irregular heart rhythms is clear
D．In modern society, sudden deaths take place much less because of higher medical levels

单项选择题

A．soB．sinceC．ifD．and

A．so
B．since
C．if
D．and