a quarter of a mile的用法和样例：
- He led by three lengths after a quarter of a mile.
- After jogging a quarter of a mile he was sweating and panting.
- They walked a quarter of a mile down the mountainside.
- I went out the back way and walked a quarter of a mile to the railroad tracks.
- The canoe first sent adrift was floating before the air, quite a quarter of a mile above him.