问题补充:
This is usual way of solving the problem. Can you think of unusual way?
A. a; a
B. a; an
C. an; an
D. an; a
答案:
A. a; a
(答案→)B. a; an
C. an; an
D. an; a
解析:本题考查的是不定冠词an和a的用法,当第一次提到某物时,要用不定冠词a或an,第一空后接的usual的首个音标为辅音音标,用不定冠词a,而后一空的unusual的首个音标为元音音标,故用不定冠词an,故选答案为B