a nail-biting finish的用法和样例：
- I can feel a nail sticking into my shoe.
- This one is different, a nail biter, a shouter, a surprise, and worth every guacamole and chips.
- He taped a nail in slowly to spilt the thin board.
- I stood on a nail, and my foot's very sore.
- His speech was always polished to a nail.