know by heart

• vi. 背(记住)

know by heart的用法和样例：

例句

用作不及物动词 (vi.)

1. The boy soon learned the poem by heart.
   这男孩不久便能熟背这首诗了。
2. All you have to do is learn it by heart.
   你只要做的就是把它背出来。