从6名短跑运动员中选出4人参加4×100 m接力赛．试求满足下列条件的参赛方案各有多少种？

(1)甲不能跑第一棒和第四棒；

(2)甲不能跑第一棒，乙不能跑第四棒

—Excuse me, could you tell me _____ later on?

—Wait a minute. It is coming in ten minutes.[ ]

A. if the next train arrives

B. if the next train will arrive

C. when the next train arrives

D. when will the next train arrive