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。
I had been out since I was 17.
我从17岁起就公开我是同性恋。
The children are completely out of control since their father left.
这些孩子自他们的父亲离开后就无法无天了。
It's been an age since we've seen them.
我们有很长一段时间没有见到他们了。