gwd-1-10 一句话的结构

lansere

文章中： Low levels of straying are crucial, since the process provides a source of novel genes and a mechanism by which a location can be repopulated should the fish there disappear. 哪位说说最后这几个词的语法是怎样的好么？不懂：（。。。谢谢：）

题目中也是一样的结构，猜得出意思，不知道语法关系：（

1. an environmentally degraded stream could be recolonized by new salmon populations should the stream recover

lansere

thanks !

yuying8124

虚拟语气:如果那里的鱼消失

A: 如果那里的河流恢复

有时if引导的状语从句可以省略 if，而把从句中的动词 were, had 或 should 移到主语前面

Molybdenum

an environmentally degraded stream could be recolonized by new salmon populations should the stream recover

我其实也想知道为什么的，hehe，

populations ( if )the stream should recover