1.看守
2.值班,当班,提防着
1.prepared against attack
2.thinking or behaving carefully, so that you do not say or do something that you did not intend to
1.Many South Korean soldiers on guard no longer present a rough, sunburnt face to the enemy, a report said Friday.
周五，据一项调查显示很多韩国值勤士兵面对敌人不再是一张粗糙，晒过的脸。
2.We must be on guard not to let the enemy spies worm(themselves) in.
我们必须特别警惕，不让敌人的特务钻进来。
3.Whenever I went out with him on weekends, I used to struggle to think up things to say, feelmg on guard.
无论什么时候我与他一起去度周末，我都会警惕的捏造各种故事和话题去用作一路上的谈资。
4.Inside the great keep Robin darted into a little room on the right of the doorway, where the only man on guard lounged carelessly.
在大城堡内，罗宾冲进城门右边的一间小房子，这里只有一位看守者不关心地卧着。
5.They would not be so much on guard for the former, but fear the latter.
对于前者，他们不会加以提防，而对后者却常常提心吊胆。
6.Each of us must be on guard against the enemy of our souls and never give place to the devil (Eph. 4: 27).
我们每个人都该儆醒守望，对抗我们灵魂的仇敌，并且永远不给魔鬼留地步（以弗所书4章27节）。
7.We do not believe that he has actually pulled out of Michigan. We are going to stay on guard.
我们相信他（麦凯恩）并未真的从密歇根撤出，我们要保持警惕。
8.Now the angels stood on guard at the gate of the garden with swords in their hands, never to allow the return of Adam and Eve.
现在，天使拿了一把刀剑站在伊甸园门口守卫，永远不让亚当和夏娃回来。
9.As a pregnant woman, you need to be on guard for some of the more common symptoms of a yeast infection.
作为一个怀孕的妇女，你需要提防真菌感染的一些更普遍的症状。
10.Cech's immediate reaction was to feel sorry for Helton, as well as putting himself on guard against anything similar.
切赫当时立刻的反应是替赫尔顿遗憾，作为门将他自己也会面对类似的情况。