今日阅读：

②The city at one time must have been prosperous, for it enjoyed a high level of civilization. Houses -- often three storeys high -- were built of stone. They had large rooms with beautifully decorated walls. ③The city was equipped with a drainage system, for a great many clay pipes were found beneath the narrow streets.

节选《新概念英语3 An unknown goddess》

【生词】

prosperous adj.繁荣的

storey n.楼层

昨日复习提要：

昨天学习了主要学习了两点， ①some time, sometime, sometimes的不同,尤其是当sometime做形容词表示“以前的”时，大家都不太熟悉这个用法。②discovery表示发现，有时候也作发现物讲，常与make连用。

昨天文章如下：

at a time与at one time意思截然不同，one，ones，once的区别？

今日文章解读：

The city at one time must have been prosperous, for it enjoyed a high level of civilization. Houses -- often three storeys high -- were built of stone. They had large rooms with beautifully decorated walls.

这座古城肯定一度很繁荣，因为它曾享有高度的文明，房子一般有3层楼高，用石块修建。里面房间很大，墙壁装饰华丽。

（1）at one time的含义详解

at one time的意思是“一度”“曾经”，这是一个常用搭配，需要注意的是，如果把one换成a，虽然都是表示“一个”，但是含义是不同的。

①at a time的意思是“每次”或“一次”，比如：

Focus on one subject at a time.

每次集中精力在一件事情上。

②at one time表示“曾经”，“曾经”这个词在中文里就能看出其使用的场合应该是表示过去，所以当at one time出现时，句子应该是过去时。比如：The song had a great vogue at one time. 这首歌曾风行一时。

③同样表示“曾经”含义的单词once

I once went there with my brother.

我曾经同我弟弟去过那里。

虽然注意区别在于，once表示曾经时，词性为副词，用来修饰动词。而at one time是介词短语，位置相对较自由。

④one与ones

与once发音相似的ones，可以作代词来表示单数名词的复数。比如：

There were a number of well-known scientists in the last century, but Albert Einstein was one of the more interesting ones. 上世纪有许多著名科学家，但是爱因斯坦是其中较为有影响的一个。

在这个句子中ones就是来指代前面提到的scientists，因为是复数，所以原来由one来指代单数的情况下多了s。