题目选项分析

Organized in 1966 by the Fish and Wildlife Service,the Breeding Bird Survey uses annual roadside counts along established routes to monitor population changes of as many, or more than 250 bird species, including 180 songbirds.

Organized in 1966 by the Fish and Wildlife Service,the Breeding Bird Survey uses annual roadside counts along established routes to monitor changes in the populations of more than 250 bird species, including 180 songbirds.