Answer:
four layers
Most rainforests are structured in four layers: emergent, canopy, understory, and forest floor.
Explanation:
Answer:
The Cell.
Explanation:
Living organisms are composed of single or multiple cells. The cell is termed the building block of life. Single cell organisms are called unicellular while multiple cell organisms are called multicellular. A single cell organism is capable of performing all the basic functions of life like reproduction, respiration etc
<span>Controlled variable is a variable that was made constant in the research. That was because the controlled variables can influence the dependent or independent variable. If the variables is not made constant, it can alter the research result and made it invalid.
In this case, </span>the caffeine and alcohol intake might alter the physical activity or the blood glucose so it should be controlled.
