我经常读这首诗，已经把它背下来了。

I've read the poem so often that I know it ___by ___heart.

作为忠实粉丝，我能熟记这部电影的所有经典台词。

As a big fan, I know all the movie's famous lines ___by ___heart.

他在考试前一晚把所有公式都背熟了。

He memorized all the formulas ___by ___heart the night before the test.