Question

We can never expect    bluer sky unless we create     less polluted world.

A. a; a                             B. a; the              C. the; a                          D. the; the

Answer 1

A

解析:

sky和world原本是独一无二的,但这里前面都有了形容词修饰,表示会出现一个什么样的sky和world,这里就属于泛反指了.