在某一时刻 at certain time
在特定的时间 at certain times
在某个时间at a certain time
例句:Payment at a certain time after sight.见票后若干日付款.
例句:Animals can be conditioned to expect food at certain times.
可以训练动物定时等待喂食.
在某一时刻 at certain time
在特定的时间 at certain times
在某个时间at a certain time
例句:Payment at a certain time after sight.见票后若干日付款.
例句:Animals can be conditioned to expect food at certain times.
可以训练动物定时等待喂食.