问题
选择题
More and more carbon dioxide is being released into the air，________the more severe global warming effects.
A．contributed to
B．to contribute to
C．contributing to
D．to be contributed to
答案
答案：C
C 考查非谓语作状语。句意：越来越多的二氧化碳被释放到空气中，导致温室效应更严重。contribute to 导致，促使。空格处为现在分词作结果状语。