A.) Veins in the pulmonary circuit carry oxygen-rich blood
red blood cells are used to circulate oxygen through out the body, thus it is true.
Answer:
a control
Explanation:
you need something to compare it to to see if anything happens
Answer:Four spheres of earth are:1)Lithosphere(land) 2)Hydrosphere(water) 3)Biosphere(living things) 4)Atmosphere(air).
Energy and matter flow through Earth's four spheres.Energy flows through the atmosphere and hydrosphere mostly by convection.The continuous cycling of matter and energy through earth's system makes life on earth possible .Others are driven by energy from the sun.
Explanation: