The adult technique is used on people of ages 12 and older
Hey There!
Here is your answer:
Your answer is that a experiments should be controlled because the experiment could go out of control which could harm or hurt someone.
Also the definition of a controlled experiment is a part of the experiment that's not touched.
Ex: Water is your controlled experiment that's because our not doing anything to the water.
If you need anymore help just ask me!
Hope this helps!
Answer:
They bring dissolved nutrients to the surface of the ocean. They decrease the levels of oxygen at the surface of the ocean. They decrease the amount of nutrients at the surface of the ocean.
Explanation: