Frank with his two sisters London by train which at 8:30 next morning.A. is leaving for;

问题补充：

Frank, with his two sisters, London by train which at 8:30 next morning.

A. is leaving for; will leave

B. are leaving for; leaves

C. is leaving for; leaves

D. will leave for; will leave

答案：

A. is leaving for; will leave

B. are leaving for; leaves

(答案→)C. is leaving for; leaves

D. will leave for; will leave

解析：句意：Frank和他的两个妹妹将要乘明天8:30的火车去伦敦。此处第一空用进行时表示将来时，第二空表示固定时间表用一般现在时。故选C。