in a day的用法和样例：
- Can I go there and back in a day?
- Rome was not build in a day.
- He used to be able to cycle50 miles in a day, but he's past it now, I'm afraid.
- In a day, a doctor may write (out) 30 prescriptions for patients.
- He makes nothing of walking 20 miles in a day.
- Rome was not built in a day.
in a day的相关资料：