The materials carried by the circulatory system include which of the following? (1) blood, (2) hormones, (3) oxygen, (4) cellular wastes.
a. 1 only
b. 1 and 2
c. 1, 2, and 3
d. 1, 2, 3, and 4

Anybody wanna ? (picture included? )

Which one of the following research methods can show cause and effect

Contrast the force of gravity between these pairs of objects: 1-kg mass and a 2-kg mass that are 1 m apart; a 1-kg mass and a 2-kg mass that are 2 m apart; and two 2=kg masses that are 1 m apart. i dont understand.