Question

( )I was walking along the street ____I met a friend of mine. A.while B.when C.as D.then

Answer 1

B.
首先，C、D肯定不选，就看A、B
while 表状态，met是一瞬间的。
但如果是i met a friend of mine while i was walking along the street.这就对了

Answer 2

B吧，要我选我就选B，为什么我也不知道，语感吧