问题补充：
—When will the engineer go to Singapore?
—Oh，I don’t know when he Singapore．When he Singapore，I will call you．
A. leaves for；leaves for
B. will leave for；will leave for
C. will leave for；leaves for
D. leaves for；will leave for
答案：
A. leaves for；leaves for
B. will leave for；will leave for
(答案→)C. will leave for；leaves for
D. leaves for；will leave for
解析：从句中他什么时候动身去新加坡指的是将来发生的事情,用将来时态.他什么时候动身去新加坡叙述的是客观存在的事情,用一般现在是,所以选C.
