Answer:
20.9 percent
Around 78% of the air is nitrogen gas, and only 20.9% is oxygen.
Explanation:
20.9 percent
Around 78% of the air is nitrogen gas, and only 20.9% is oxygen.
Hope this helps.
By slowly introducing the changes and not implementing them all at once.
Answer: digestive and excretory completes the sentence.
The answer is C: Number of contractions of the heart that occur in one minute when your body is at rest.