我们必须在7点30分准时离开。

We have to leave at 7:30 ___on ___the ___dot.

他给了他一个地址，告诉他六点整到那里。

He gave him an address and told him to be there at six ___on ___the ___dot.

会议将在上午10点整开始，所以请提前到达。

The conference will begin at 10:00 AM ___on ___the ___dot, so please arrive early.