“在某人多少岁时”用介词“in”还是“on”

Question

如题所述

Answer 1

没有用on的,如“在他五十几岁时”用in his fifties,
如果直接表达具体的岁数可以用at,at the age of 10/ at 10

Answer 2

在某人多少岁时
At the age of one's