If water bees increasingly scarce in decades ， water shortage will bee a hot issue all over the world.
A. ing
B. having e
C. to e
D. to be ing
网友回答
A. ing
B. having e
(答案→)C. to e
D. to be ing
解析：选C 考查非谓语动词。句意：如果在未来的几十年当中，水变得越来越紧缺，那么用水短缺将成为全世界的热点问题。此处是指未来的几十年，故应用不定式to e作后置定语，表将来，修饰名词decades。