He had a way of throwing Helen off guard with his charm when she least expected it.

他有办法用他的魅力让海伦在最意想不到的时候失去戒备。

The pastoral elegance of this little simile really catches us off guard.

这个有着田园诗情画意般优雅的小比喻确实让我们毫无防备。

This catches me a little off guard.

这番话让我有点猝不及防。

Her betrayal took me completely off guard.

她的背叛让我完全措手不及。

The pace of this change has certainly caught hotels off guard.

社会媒体的变化速度让酒店措手不及。