Suppose a list is $2,9,5,4,8,1.$ The bubble sort is being used to sort the list in ascending order. After the first pass of bubble sort, the list becomes

$2,9,5,4,1,8$

$2,5,4,8,1,9$

$2,9,5,4,8,1$

$2,1,5,4,8,9$

$2,5,9,4,8,1$