from和since的区别
问题描述：
from和since的区别
我想问的是from和since后加时间的区别,
譬如,from 1990和since 1990的区别
答
from 用在已完成的形式,通常 要加 上 to
from 1990 to 2000 ...
since 用在还在发生
给你例子
Mr.A was the president from 1900 to 2000
Mr.A is the president since 1900