Final answer:
The Montreal Protocol will take time to be successful due to slow recovery process, need for constant vigilance, and the requirement of international cooperation.
Step-by-step explanation:
The Montreal Protocol will take some time to be successful due to several factors. First, the recovery process of the ozone layer is slow because the banned chemicals, such as CFCs, take many years to reach the stratosphere and linger there before breaking down. Secondly, constant vigilance and monitoring are needed to prevent illegal production and emission of these chemicals, which can hamper the recovery efforts. Finally, the protocol requires international cooperation and participation, particularly from developing countries, to achieve worldwide production and elimination of the harmful substances.