Why does it rain?
Rain is droplet of water falling from the sky. In the water life cycle, water from water bodies on earth evaporates and become clouds. The water droplets in the cloud coalesce and get bigger. When clouds become saturated, or get bigger and bigger, that the air can no longer hold it, they fall down as rain.
Instruction: Why does it rain?
Context: 
Response: Rain is droplet of water falling from the sky. In the water life cycle, water from water bodies on earth evaporates and become clouds. The water droplets in the cloud coalesce and get bigger. When clouds become saturated, or get bigger and bigger, that the air can no longer hold it, they fall down as rain.