since的用法
一个问题：
--What was the party like?
--Wonderful.It is years ____ I enjoyed myself so much.
A.after B.before C. when D.since
请问since 和before 有什么区别
参考答案:这里应该用 D.since
此题改自《Longman》since条的一个例句：
It's been years since I enjoyed myself so much as last night.我已有好多年没有像昨晚那么痛快了。
It has been +一段时间+ since sth. happened. 是一个很有用的句型。现在常写作：
It is +一段时间+since sth. happened.