— Must I return this book today, Mrs. Smith?    

— No, you ______. You may keep it until next week. [ ]

A. may not

B. can't

C. must not

D. needn't

肠管迅速膨胀，肠壁变薄，可引起等渗性脱水的是

A．尿流突然中断
B．排尿困难
C．膀胱刺激征
D．尿潴留
E．黏膜恶性变