Two and half centuries later, in the first spring of the Civil War, Fort Monroe was a lonely Union redoubt in the heart of newly Confederate territory. Its defenders stood on constant guard.

两个半世纪之后，在内战爆发后的第一个春天，Fort Monroe成了新成立的联邦领土内为数不多的联邦军据点之一，士兵们一直绷紧神经保卫着。

youdao

The valve consists of a guard cage, spring, valve disc, retaining ring and seat. It can be combined with pipe fittings such as reducing couplings, drain elbows, etc.

阀由警戒装置、弹簧、阀碟、扣环和阀座组成，可以和许多管件连接，如缩径管接头、排水弯头等。

youdao

As you lift the saw, the spring-tensioned telescoping guard will automatically close under the blade.

抬起圆锯后，弹簧绷紧压入的保护罩会自动在锯片下方关闭。

youdao

U.S. and coalition forces were already on guard against an expected Taliban spring offensive even before bin Laden's death, Campbell added.

CNN: U.S. granted access to speak to bin Laden's wives