the man was hit on the head ___ a stone while traveling in the mountain a.with b.by为什么选b 不选a a 用.

the man was hit on the head ___ a stone while traveling in the mountain a.with b.by为什么选b 不选a a 用.
the man was hit on the head ___ a stone while traveling in the mountain a.with b.by
为什么选b 不选a a 用.

the man was hit on the head ___ a stone while traveling in the mountain a.with b.by为什么选b 不选a a 用.
表示被动,用by引导