Background Paragraph: Because of its temperature, the atmosphere emits infrared radiation. For example, on clear nights Earth's surface cools down faster than on cloudy nights. This is because clouds (H2O) are strong absorbers and emitters of infrared radiation. This is also why it becomes colder at night at higher elevations. 
Story: David was visiting Europe last summer. First he visited London. To his dismay, it was overcast all night. Then he flew to Rome. There the sky was as clear as you could get at night. David was very happy about it.
In London, would less or more infrared radiaton be emitted at night than in Rome? In Rome, would less or more infrared radiaton be emitted at night than in London? In which place less ifrared radiation would be emitted at night, London or Rome? In which place less infrared radiation would be absorbed in the atmosphere, London or Rome? In which place more ifrared radiation would be emitted at night, London or Rome? In which place more infrared radiation would be absorbed in the atmosphere, London or Rome? In which place the Earth's surface would cool down faster, London or Rome? In which place the Earth's surface would cool down slower, London or Rome? Would Earth's surface cool down faster or slower in London than in Rome? Would Earth's surface cool down faster or slower in Rome than in London?