As a rule, this hotel offers 18 percent discount for guests staying on Friday and Saturday.
A. a; the
B. the; the
C. the;不填
D. an;不填
网友回答
A. a; the
B. the; the
C. the;不填
(答案→)D. an;不填
解析：考查冠词：第一空填an，指18%的折扣，第二空不填，泛指客人，句意是：通常情况下，旅店给周五周六住宿的客人打18%的折扣。选D。