问题补充:
global temperatures rising, the UN Climate Change Conference was held in Cancun(坎昆), Mexico last year.
A. Prevented
B. Preventing
C. Having prevented
D. To prevent
答案:
A. Prevented
B. Preventing
C. Having prevented
(答案→)D. To prevent
解析:考查不定时做目的状语。 为了防止全球气温增长,去年联合国在墨西哥坎昆召开了气候大会。