1. Suppose the letter A is placed in an empty queue, followed by the letters B and C, in that order. Then suppose that a letter is removed from the queue and the letters D and E are inserted. List the...

1.
Suppose the letter A is placed in an empty queue, followed by the letters B and C, in that order. Then suppose that a letter is removed from the queue and the letters D and E are inserted. List the letters that would be in the queue in the order they would appear from head to tail. If a letter is now removed from the queue, which letter will it be?

2.
Suppose a tree has four nodes A, B, C, and D. If A and C are siblings and D’s parent is A, which nodes are leaf nodes? Which node is the root?