Answer:
They provide a habitat for fish, frogs and other animals.
soil is essential as it provides nutrients to plants. water is used for drinking and many other things.
A Classic Sun-Burn Is A Perfect Example Of A First-Degree Burn
Answer: Those who studied alone were exposed to the CONTROL condition.
Explanation: In an experiment, there are usually 2 conditions.
1.) The Natural condition
2.) The controlled condition
In this case, the controlled condition, the researcher is testing one person at a time as against testing with a group of people. This is to ensure that the researcher can adjust the conditions of the other experiment by studying just one person at a time.