问题补充：
--- Hello, I to ask if I can book two tickets for tonight’s film.
--- Sorry, we’ve already sold out.
A. phone
B. will phone
C. am phoning
D. have phoned
答案：
A. phone
B. will phone
(答案→)C. am phoning
D. have phoned
解析：
考查时态.你好,我打电话时想问是否能预订两张明晚的电影票._抱歉,我们已经售完了.结合语境可知上文描述的是现在正在进行的动作,故用现在进行时态,选C.
