since引导时间状语从句或愿因状语从句。
since：
prep.自从;自…以后;从…以来;(表示气愤)何曾，什么时候。
conj.因为;由于;既然;从…以后;自…以来。
adv.自…以后;从…以来;此后;后来。
扩展资料
Shes a changed woman since she got that job.
她自从得到了那份工作，变得判若两人。
Shes been using since she was 13.
她从13岁起就吸毒。
His quality of life has improved dramatically since the operation.
手术后他的生活质量大大改善了。
Its a long time since they left.
他们已经离开很久了。
Its been two weeks now since she called.
她到现在已经有两个星期没来电话了。
