问题补充：
Children exposed to air pollution are moreto suffering from different diseases.
A. possible
B. probable
C. likely
D. certainly
答案：
A. possible
B. probable
(答案→)C. likely
D. certainly
解析：单词辨析。句子缺少表语，而D是副词，不能作表语，排除D；possible和probable不能用人作主语，所以选C。sb. be likely to do sth.某人很可能会做某事。
