I've got a full mark on this test.
这次考试我得了满分。
You must have prepared very well.
你一定准备得非常好。
Sure thing. I've learned every question by heart.
当然。我己经把每道题都背下来了。
No wonder you did a perfect job. You deserve it.
怪不得你得了满分。这是你应得的。
learn by heart 记住，背诵
perfect a.完美的;完全的;完成时的 vt.使完美