这条单行道只能向北行驶。

This ___one-way street only allows traffic to head north.

这段对话完全是单向的，只有他在不停地说。

The conversation was completely ___one-way, with only him talking nonstop.

我买了一张单程票去巴黎，因为回程日期还没确定。

I got a ___one-way ticket to Paris since my return date isn't fixed yet.