You'll need to learn this off by heart.

你需要把它背下来。

Sorry, I haven't learned it off by heart.

对不起, 我还没有把它背下来。

They had to learn all the chants and prayers off by heart so that they were preserved and handed down, unchanged.

他们必须背诵赞歌和祈祷文，以便将它们保存下来，不变地流传下去。

There is absolutely no excuse for a mistake on a CV, you need to check it over until you know it word for word, off by heart.

不能为简历上出现的错误找借口，你需要仔细检查知道你每一个词都清楚，倒背如流。

At the end of this lesson, you will have a complete self introduction that is ready to use, and ready for you to learn off by heart.

在这节课的最后，你将会有一个完整的可以立即使用的自我介绍，你可以记忆。

I read the book o' Revelations until I know it off by heart, and I never doubt when I'm waking, and in my senses, of all the glory I'm to come to'.

我读了《启示录》，直到我把它牢记在心，我从不怀疑我什么时候醒来，在我的感官中，我将获得所有的荣耀。