I was in some doubt as to whether the Corporal had ______ us accidentally on his way out of the town or if he'd been deliberately tasked.

【正确答案】 B

【答案解析】 动词词组辨析。选项中，只有bump into(邂逅，相遇)与accidentally搭配合理，意为“偶然的邂逅”。故答案为B。crash on“撞击”；fall against“跌倒”；puzzle about“感到迷惑”。