用 4、5、6、8 这四个数字组成一个介于 5 000 和 6 000 之间的最大数。 答：___

1. Determine the thousands digit based on the given range

The number must be between $5000$ and $6000$. Therefore, the thousands digit must be $5$.

2. Arrange the remaining digits to form the greatest possible number

The remaining digits are $4$, $6$, and $8$. To form the greatest number, arrange these digits in descending order: $8$, $6$, $4$. The number is $5864$.