We can have blue sky if we create less polluted world.A. a. aB. a, theC. the, aD. the, t

We can have blue sky if we create less polluted world.
A. a. a
B. a, the
C. the, a
D. the, the

(答案→)A. a. aB. a, theC. the, aD. the, the解析：此题重点考查不定冠词的用法，表示泛指。

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