She's a changed woman since she got that job.
她自从得到了那份工作，变得判若两人。
She's 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。
It's a long time since they left.
他们已经离开很久了。
It's been two weeks now since she called.
她到现在已经有两个星期没来电话了。