burn the midnight oil 熬夜工作
【讲解】
该习语从字面上理解是“烧夜油灯”，意即 “夜里点灯照明”，引申为“开夜车，熬夜工作”。
【对话】
A：You look sleepy. Have you been burning the midnight oil recently?
A: 你看上去很困。最近是不是熬夜用功呢？
B: Yes, I've been preparing for my finals.
B：是啊。我一直在准备期末考试。
A: Well, you must have had adequate preparation.
A: 那你一定准备得很充分了？
B: I can't say!
B：这可不敢说！
