Watch your head because there's not much headroom up here.

小心碰头，因为头顶上方的空间不大。

It has a small bowl, not a lot of headroom here.

杯身较小，空间也有限。

That puts an upper limit on the age of sequenceable DNA, but one that still leaves a million years more headroom.

这就给可测序DNA的年龄设定了上限，但仍留有100万年的空间。

The headroom, the amount you had to spare in March, that was clearly already gone.

净空，你在三月份必须腾出的空间， 显然已经没有了。

The smell of so many people crowded together was offensive. The breadth of the vessel was narrow and the headroom below deck minimal.

这么多人挤在一起，气味简直让人受不了。船舱狭窄又很低矮。