请教three years later与three years ago的区别？

1) three years later 以过去某一点为参照,意思是：“三年后”如：In 1986,I went to Beijing,and three years later,I returned to my hometown to be a teacher in a primary school.

2) three years ago 以现在为时间点为参照,往回数三年,就是“三年前”的意思.句子用一般过去时.如：It is 2011,I am a college student now in Nanjing university,but three years ago,I was a middle school student.

另外注意：以现在为起点,往后数的三年,我们应该用 In three years,即“三年后”或“今后三年内”.如：I will buy a new house in three years.

I will finish doing this work in 3 hours.

宣统三年的银币，看过摔过摸过绝对真的，我看资料这个英文后面有点，好像是“有点宣三”问现在值多少钱？

• 200左右吧