—Is this your bicycle, David?

—No, it's not _______.  It's Helen's. [ ]

A. his

B. yours

C. mine

D. hers

关于阴囊下列错误的是（）

A.囊袋状结构

B.壁由皮肤和肉膜组成

C.由阴囊中隔分为左右两腔

D.肉膜内含骨骼肌纤维

E.精索外筋膜是腹外斜肌腱膜的延续