it is some time before与it is some time since 的区别是什么,请举例说明,

it is some time before与it is some time since 的区别是什么,请举例说明, 为啥it is some time since与it has been some time since没区别 为啥it is some time since与it has been some time since没区别谢谢了, it is some time since+...与it has been some time since+...什么区 some time it is true,some time is not. It is some time before i realize the turth.为什么用before而不能用unt it has been some time+since是什么意思 what time is it 与when is it 的区别 it's + a period of time + before/since 的区别? i am exhausted .it is going to be some time before i recover 什么时候用It be some time+since从句,什么时候用It be some time +that 从句 It is time for some bread?(同义句）