题干
If you buy ____ iphone 6s in our shopping mall, you will get ___ umbrella for free.
A：a; an
B：an; an
C：an; a
D：a; a
答案(点此获取答案解析）
B
If you buy ____ iphone 6s in our shopping mall, you will get ___ umbrella for free.
A：a; an
B：an; an
C：an; a
D：a; a
