— What happened to Tom?

— He was crossing the street ____ a motorbike hit him from behind. [ ]

A. while　

B. when

C. until

D. because

可续保定期寿险的保费要略（）。

A.高于同类的不可续保定期寿险

B.高于同期限的两全人寿保费

C.低于同期限定期人寿保费

D.低于现有合同到期时续保寿险的保费