问题补充：
Mr. Blake Shanghai in a few days. Do you know when the earliest plane on Sunday?
A. is leaving, is taking off
B. leaves, takes off
C. is leaving, takes off
D. leaves, is taking off
答案：
A. is leaving, is taking off
B. leaves, takes off
(答案→)C. is leaving, takes off
D. leaves, is taking off
解析：考查时态，由后面的时间状语in a few days，时态是将来时，短暂性动词进行时，表示将要做某事，句中有when，引导的时间状语从句，主语是the earliest plane，take off意思“起飞”，所以选C
