He fell head first down the stairs.

他倒栽葱摔下楼梯。

Hut, hut, hut: First down and haiku!

小屋，小屋，小屋。第一句是俳句。

Airlines could be first down this path.

航空公司可能会在这条道路上打前阵。

Prior to the snap, false start, five yards, defense. Still first down.

在开球之前，防守的一方提前移动，罚五码，还是第一次进攻。

Ink trapping: it is the ability of the first down ink to get hold of the overprinting ink.

油墨牵力：是先印的油墨能否把叠印的油墨牢固拉着的能力。