It is global warming not other things the extreme weather.A. that have led toB. which h

问题补充：

It is global warming, not other things, the extreme weather.

A. that have led to

B. which has caused

C. which are causing

D. that has led to

答案：

A. that have led to

B. which has caused

C. which are causing

(答案→)D. that has led to

解析：考查强调句型。强调句型的基本结构为：it is/was被强调成分that/who其它成分；最大的特点是把it is…that/who…去掉，句子仍然成立。本题强调的是主语global warming.句意：正是全球变暖而不是其它的事情导致了极端天气。故D正确。