是“整点”不是“准点”!
比较权威的汉英词典上用的是integral point,自己加到句子里吧,因为不知道你指的是什么车。介词可以用at,动词用一般现在时就可以了。比如:
The shuttle buses depart at integral points./The coach departs at every integral point.
The train will depart punctually .
或The train will depart at 10 o'clock sharp .
火车10点整出发!
The train will depart on time.