all at once ; at once 的区别.15填什么?
问题描述：
all at once ; at once 的区别.15填什么?
,the young woman happened to mention that she had lost her purse that afternoon,15_____ I realized where I had seen her
答
all at once是突然的意思,at once 是马上,立即的意思.
15填all at once.at once一般放在句尾.