一个英语语法问题请看下面的句子：Afewdayslater,Dresdenwasbattlingitsworstfloodsince1501.既然句子用了since+时间点,但为什么句子不用完成时呢?是不是since有其他意思?

Question

一个英语语法问题
请看下面的句子：
A few days later, Dresden was battling its worst flood since 1501.
既然句子用了since + 时间点, 但为什么句子不用完成时呢?是不是since 有其他意思?

Answer 1

since的四种用法
1） since +过去一个时间点（如具体的年、月、日期、钟点、1980, last month, half past six）.例如：
I have been here since 1989. 1989起,我一直在这儿.
2） since +一段时间+ ago.例如：
I have been here since five months ago. 我在这儿,已经有五个月了.
3） since +从句.例如：
Great changes have taken place since you left. 你走后,变化可大了.
Great changes have taken place since we were here. 我们走后,变化可大了.
4） It is +一段时间+ since从句.例如：
It is two years since I became a postgraduate student. 我考上研究生有两年了