Answer:
A. body muscles
The pressure needed to pump blood back to the heart is produced by the <u>body </u><u>muscles </u><u>.</u>
D. The final substance in Beaker A is a mixture and in Beaker B is a pure substance.
Hope this helps! 159.2086<span>Have a Good Day!</span>
Answer : The new pressure if the volume changes to 560.0 mL is, 280 mmHg
Explanation :
According to the Boyle's, law, the pressure of the gas is inversely proportional to the volume of gas at constant temperature and moles of gas.

or,

where,
= initial pressure = 560.00 mmHg
= final pressure = ?
= initial volume = 280 mL
= final volume = 560.0 mL
Now put all the given values in the above formula, we get:


Therefore, the new pressure if the volume changes to 560.0 mL is, 280 mmHg