a year later 是指一年后
A year later,she became a queen.
in a year 在一年中;一年内;一年后
There are 365 days in a year.一年有365天
People in the city died in a year.一年之内,城里的人都死了.
I will be back in a year.我一年后回来.
a year after 没有吧 一般用after a year
After a year,we trod respective journey,一年后我们踏上了各自的旅途
past a year 也没有,只有 in the past year 在过去的一年
In the past year,we learned a lot.