在演讲前，我把整篇演讲稿都背下来了。

I memorized the entire speech ___by ___heart before the presentation.

那个小女孩能熟记所有的舞步。

The little girl can recite all the dance steps ___by ___heart.

他是个了不起的演员，能为每个角色记住所有的台词。

He's an amazing actor who learns all his lines ___by ___heart for each role.