[转载]It+be+时间+before/since/when/that 句型辨析
2012-05-10 16:36阅读:
It+be+时间+before/since/when/that 句型辨析
I. since
1.It is/has been+时间段+since sb did sth某个动作发生持续多久
eg:It is/has been three years since he finished the work.
自从他完成这项工作已经三年了.
