alertness例句

The drug improved mental alertness.
该药有助于提神。

Alertness, calmness, courage : he could see them all in the youngster's face.
机警, 镇定, 胆量,都摆出在这年青人的脸上.

We must maintain a military standard, an alertness, and never vary it.
我们必须保持军队的准则, 应当随时注意,切勿随时变动.