within
注意下面四句里都用of而不用from:
- I live within an easy walk of the park.
- There is no shop within a mile of his house.
- He returned within an hour of his departure.
- He called on me within an hour of his departure.
within an hour of his departure在第三句里是“在他动身以后的一小时以内”,在第四句里是“在他动身以前的一小时以内”。第三句里的of可以改作after。