Anchor: The clearest challenge for Customs would be to manage a workload that was growing rapidly and that could not be expected to taper off.
Entailed: Managing a rapidly growing workload with no end in sight is the biggest obstacle Customs is facing.
Contradiction: Increased workload is a problem for Customs but hardly the biggest challenge being faced.
Contradiction: the dogs are asleep
Contradiction: A young person has a camera.
Contradiction: A man is climbing a radio tower.
Contradiction: I have thought about this.