When I was doing shopping in the market the other day, I _____ an old friend of mine, who I hadn’t met for twenty years.

A．came up

B．came over

C．came across

D．came about

直肠肛管手术时常采用的体位是（）。

A.肘膝位

B.左侧卧位

C.截石位

D.蹲位

E.弯腰前俯位