Fact 1: If the amount of available food and water decreases in an environment then animals may leave that environment to find food and water.

Fact 2: Food, water and air are the essentials of life on earth.

Given the two facts above, answer the question "What can decrease in an environment, and may cause animals to leave?" with the following options: 
- essentials of life
 - competition
 - wind speed
 - living things
 - single-celled organisms
 - deforestation
 - biodiversity
 - rock content


 

 essentials of life        