问题
选择题
It is _____ unusual thing for us to find _____ UFO. [ ]
A. a; a
B. an; an
C. a; an
D. an; a
答案
答案:D
It is _____ unusual thing for us to find _____ UFO. [ ]
A. a; a
B. an; an
C. a; an
D. an; a
答案:D