TT GWD 6-27

Q27:

In Scotland,
the number of wild salmon have been reduced because of uncontrolled deep-sea
and costal netting, by pollution, and by various other threats to the
fish’s habitat.

1. number of wild salmon have been reduced because of uncontrolled
        deep-sea and coastal netting
2. number of wild salmon is reduced because deep-sea and coastal
        netting is not controlled
3. numbers of wild salmon has been reduced because of uncontrolled
        deep-sea and coastal netting
4. wild salmon’s numbers are reduced by deep-sea and coastal
        netting that is not controlled
5. wild salmon’s numbers have been reduced by uncontrolled
        deep-sea and coastal netting

   Answer:

numbers 有一群群的意思。 另外这个题考的是 by ..., by ..., and by...的平行结构。

nnd，我说这题怎么想不明白，没看见by pollution前面的逗号！！