He had ever climbed this mountain several months before, but _____ he couldn't find the way this time.

[      ]

A. anyhow

B. somehow

C. somewhat

D. sometime

输尿管结石发生肾功能不全的原因是

A．肾绞痛
B．侧结石梗阻
C．饮水过少
D．输尿管黏膜损伤
E．排尿困难