非甾体抗炎药引起的溃疡半数以上是（）

A．无症状性溃疡 

B．幽门管溃疡 

C．胃角部溃疡 

D．球后溃疡 

E．复合性溃疡

I left for the office earlier than usual this morning ______ traffic jam.

A. for the sake of B. in case of
C. at the risk of
D. in spite of