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题库 / Prep2007E1-SC-2
Organized in 1966 by the Fish and Wildlife Service, the Breeding Bird Survey uses annual roadside counts along established routes for monitoring of population changes of as many as, or of more than 250 bird species, including 180 songbirds.
for monitoring of population changes of as many as, or of
to monitor population changes of as many, or
to monitor changes in the populations of
that monitors population changes of
that monitors changes in populations of as many as, or
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笔记：B选项那个or在那里干嘛的
那是个要连接平行的关键词啊。。
as many as ... or more than 250 重复了，意思就是more than 250 （等于或大于250/大于250）
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