at that time经常和一般过去时或过去进行时连用。例如：

At that time, our ship was tied up at this harbor.当时我们的船停靠在这个港口。

At that time my mother took in paying guests.那时候，我妈妈接待房客。

At that time, Rome subjected all Italy to her rule.那时罗马把整个意大利置于自己的统治之下。

The family were listening to the girl singing at that time.当时，一家人在听那个女孩子唱歌。