GWD-1-Q11:

保持微笑

According to the passage, human activity has had which of the followingeffects on salmon populations?
                           

1. An increase in the     size of salmon populations in some previously polluted rivers
   

A decline in the number of salmon in some rivers定位第一段Line 1-7

A decrease in the     number straying salmon in some rivers

A decrease in the     gene flow between salmon populations that spawn in polluted streams and     populations that spawn in pristine streams

A decline in the     vulnerability of some salmon populations to the effects of naturally     occurring habitat destruction


请问E为什么不对，S的栖息地破坏了？是因为它是文章的内容，没有推断？？？