Answer:
Moist walls - gases dissolve in the moisture helping them to pass across the gas exchange surface. Permeable walls - allow gases to pass through. Extensive blood supply - ensuring oxygen rich blood is taken away from the lungs and carbon dioxide rich blood is taken to the lungs.
Control group
Explanation:
The control group usually serves as a reference for comparison during a scientific investigation.
What is a control group?
- The control group is an experimental group not being tested for.
- it does not receive any modification or design from the scientist.
- It is designed as a reference for the main experiment
- Often times, it is isolated from the main experiment and the independent variables cannot influence the outcomes of the experiment.
Learn more:
Controlled experiment brainly.com/question/1621519
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Answer:
Force = 78 N
Explanation:
Given data:
Mass = 39 Kg
Acceleration = 2 m/s²
Force generate = ?
Solution:
Formula:
F = ma
F = force
m = mass
a = acceleration
Now we will put the values.
F = 39 Kg × 2 m/s²
F = 78 Kg.m/s²
Kg.m/s² = N
F = 78 N
