These men are always on their guard.

这些人随时戒备着。

Little boys, as well as grown up people, have to be often on their guard.

无论小孩子，还是长大以后，都要做好自己的守护工作。

The coxswain pronounced a few words in his bizarre language, and no doubt he alerted his men to keep on their guard.

小艇艇长说了几句他的奇怪语言，当然是他通知水手们，大家要小心警戒。

Now there's some credit, and more sport, in going where they boast they're on their guard against you.

现在，去他们吹嘘他们提防你的地方， 有一些功劳， 也有更多的乐趣。

" Well, the main thing is to try and convince as many people as possible that You-Know-Who really has returned, to put them on their guard." said Bill.

“是这样，尽量让更多的人相信神秘人真的回来了，让他们保持警惕。”比尔说。

In a flash this report had gone the rounds and the buyers were on their guard. I had run over to London to see the thing through, and it was the queerest sale I ever was at.

转眼之间，这份报告传开了，买家开始警惕起来。我跑到伦敦看透了这件事，这是我参加过的最奇怪的一次拍卖会。