笔直地
Bolt \Bolt\, adv.
In the manner of a bolt; suddenly; straight; unbendingly.
[He] came bolt up against the heavy dragoon.
--Thackeray.
{Bolt upright}.
(a) Perfectly upright; perpendicular; straight up;
unbendingly erect. --Addison.
(b) On the back at full length. [Obs.] --Chaucer.