翻译：“这就是我暑假最难忘的事情”

翻译：“这就是我暑假最难忘的事情”

this is the most unforgettable thing in my summer vaction

That/this was the most memorable thing that happend during my summer vacation.
That 和 this 按着上下文选一个。

It is my most unforgettable thing in the Summer Holiday!
这就是我暑假最难忘的事情.

It is the most unforgettable thing in this summer holiday.