1. have eyes for
释义 1：To be focused on or interested in something, often at the expense of other things. （对某物感兴趣，专注于某物）
e.g. He could have stayed in his position at the company and retired a millionaire, but he had eyes for being elected to public office.
e.g. Our government only has eyes for the big cities, leaving our small rural towns to rot by the wayside.
释义2：To be romantically interested in or devoted to someone. （对某人产生兴趣，专注于某人）
e.g. I know you're a little worried about me being around all of these beautiful women, but I only have eyes for you, my darling.
e.g. You can tell by the way she looks at him that Beth has eyes for Trent.
2. have someone’s number
释义：To understand or know someone or something well enough to anticipate what they will do. （知道某人的底细）
e.g. Oh, don't worry — I won't let him cheat me. I've got his number.
e.g. That team is impossible to beat—they've had our number since 2006!
e.g. I have his number——He enjoys less popularity than most other professors.
e.g. She pretends to be friendly but I have got her number——she just likes to pry into everything.
3. have someone on the brain
释义：To be thinking of someone repeatedly over a period of time; to have someone at the front of the mind. （痴迷于某人或某物）
e.g. I had Alice on the brain today, and she just called me, can you believe it?
e.g. A：Do you want Italian or Chinese tonight? I know dinner is hours away, but I just have food on the brain.
You do nothing but talk about your job; you’ve got work on the brain!
e.g. I have money on the brain, I guess.