It is since I to collect stamps. Now I have owned thousands of stamps.
A.three years , began
B. two years ago,began
C. three years,have begun
本题答案为A，我想请问C为什么错。
还有一个类似题
It three months since he came to our school
A.is
B has been
答案给了A，我没了解B错哪了？
还有就是这个句子是 主语从句 还是it做虚主语带个时间状语从句
请专家老师指点一下。
谢谢。
It is since I to collect stamps. Now I have owned thousands of stamps.
A. three years, began
B. two years ago, began
C. three years, have begun
本题答案为A，我想请问C为什么错。
【答】第一个选项是three years，没问题。第二个选项，重要是搞了解时间连词since的意思：它表示某状况自过去某时间点或某个事件以来一直持续到目前，意为“自…将来，从…以来”——这意味着，since从句中的谓语动词表示的动作一定发生在过去，因此since从句用通常过去时。故选B。
还有一个类似题
It three months since he came to our school
A. is
B. has been
答案给了A，我没了解B错哪了？
还有就是这个句子是 主语从句 还是it做虚主语带个时间状语从句
请专家老师指点一下。
【答】你的质问是正确的。It is three months...在口语中看上去简练。其实，按语法规则，主句用完成时has been更适合。因此，两种答案都对！
