Answer:
i think b i not 100%
Explanation:
im going to try c on my test
Respiratory system is refers to as the organs which are involved in breathing such as nose, throat, larynx, trachea, bronchi, and lungs. It is also known as respiratory tract.
The circulatory system is refer to as which contains the heart and the blood vessels and blood moves throughout the body in vessels. This circulatory system helps tissues to get enough oxygen and nutrients, and it helps them get rid of waste products.
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What is breathing?</h3>
When person inhale (breathe in), air enters in the lungs, and oxygen from atmosphere moves to body blood. At the same time, carbon dioxide, a waste gas, moves from blood to the lungs and is exhaled (breathed out).
Breathing process is known as gas exchange which is is essential to life.
For more information regarding breathing, visit:
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Nothing
Explanation:
Mass of the sample = 500g
Decay rate per anum = 11%
Unknown:
Mass of sample remaining after 10yrs = ?
Solution:
This is a simple percentages problem;
The radioactive sample loses 
x 500g of sample per year;
this is a loss of 55g per year;
In 10years time, the sample would have lost 10 x 55g = 550g of element.
Since our sample is not up to 550g, then no amount of sample will remain after 10yrs.
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Answer: Non-living factors in an ecosystem.
2. A large region of land with a distinct climate and certain types of plant and animals.
Explanation:
. Biosphere
b. Biome
c. Population
d. Abiotc
e. Ecosystems
f. Biodiversity
g. Food Chain
h. Aquatic
i. Community
Explanation:
Your heart muscle cells –
