input question: What is the missing first step of the following process: - These substances rise into the high atmosphere - They react with water and oxygen - This creates a more acidic rain - The rain with the high acid content falls.???
output answer: Chemicals like sulfur dioxide and nitrogen are released into the air

input question: What is the missing first step of the following process: - Bloodstream - The pancreas - Insulin lower sugar levels - Bloo sugar goes back to normal.???
output answer: Sugar enters the body

input question: What is the missing first step of the following process: - As the saltwater is heated the water becomes a gas - The salt particles sink to the bottom of the container - Gaseous water is piped into another container - Allowed to cool - The salt particles are left behind in the first container - The second container contains fresh water.???
output answer: The salt water is heated

input question: What is the missing first step of the following process: - The plants and floor absorb the the sunlight - The absorbed sunlight is converted to heat - The heat cannot escape the glass - The heat is trapped in the greenhouse - The hot air rises - The colder air at the top is pushed to the bottom - The colder air is then warmed by the floor and the plants.???
output answer:
Sunlight passes through the glass into the greenhouse