Prep2012-Pack1-SC-064 VSC002625 hard Although beavers can still be found throughout the western United States, their number has declined compared with the eighteenth century, when the abundance of beavers lured armies of European trappers into the Rocky Mountain region to slaughter them for their pelts. A. their number has declined compared with B. their numbers have compared with C. their numbers have declined since D. their numbers have in comparison to those of E. the number of them declined since
请问E中的the number of 和their numbers有什么区别? 抛开declined这个错误来看~我怎么觉得应该是the number加单数更合适啊?