Which of the following objects would best be used to understand how the human heart works?
A.
coffee filter
B.
block of wood
C.
plastic bag
D.
water pump

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i got you i did it ya know what it is just needing to fill this in for a quick task!

answerlength of time the medication is in contact with the skin(moistur level of the skin) depth of respirations blood supply to the area; all of the above; ///