直肠肛管手术后出现尿潴留的原因可能有()。
A.伤口疼痛
B.骶管麻醉
C.敷料填塞过多
D.术中输液过多
E.不习惯床上排尿
参考答案:A, B, C, E
若圆锥的轴线为正垂线,则该圆锥的主视图为(),俯视图为(),而左视图为()
It was in the beautiful park____was located by the sea____we first met our new Chinese teacher. [ ]
A. where; which
B. that; which
C. that; that
D. which; where