We understand small changes to our land can have a big impact upon our environment as we know is vulnerable enough.
A. what; which
B. what; where
C. how; where
D. how; which
网友回答
(答案→)A. what; which
B. what; where
C. how; where
D. how; which
解析：考查固定句式以及定语从句。因为small changes是名词短语，所以用what引导。第二空是考查定语从句。As we know 是插入语，可以省略，which指代先行词environment在句中做主语。句意：我们理解，对土地的小小的改变可能会对很脆弱的环境有很大的影响。