back-to-back：一个接一个的（地）；连续的（地）

e.g. I can't take two days like this one back-to-back.

像这样的日子要连续过两天，我可受不了。

e.g. I schedule all my appointments back-to-back to save time.

为了节省时间，我把所有的约会一个个紧挨着安排。

e.g. These back-to-back appointments are killing me.

这一连串的约会使得我疲于奔命。