You enqueue 4, enqueue 7, dequeue, enqueue 9. What is at the front?

• 9
• 4
• 7

What is the queue rule?

• Last in, first out
• First in, first out
• Largest value leaves first

Same four values through a stack and a queue: how do the outputs compare?

• Identical in both
• Reversed in the stack, arrival order in the queue
• Random in both

The front print job jams. What happens and what fixes it?

• The line reorders itself automatically
• Everything behind waits; cancel or restart the front job and the line flows in order
• Later jobs jump ahead of the jam

Why does a print spooler keep jobs in a queue?

• Printers print fastest in reverse
• One printer serves many in order
• Queues use less paper

Removing from position zero of a Python list is the fastest way to run a huge queue.

A student runs editor undo on a queue and oldest edits vanish last. What is the error?

• Undo needs newest first, which is stack order, not queue order
• Queues cannot store edits
• Undo needs no structure at all

Enqueue A, enqueue B, dequeue, enqueue C, dequeue, dequeue. What order leaves?

• A, then B, then C
• C, then B, then A
• B, then A, then C