Answer:
Question 1
A.) <em><u>Atoms</u></em>
Question 2
B.) <em><u>Cells</u></em>
Ventilation systems are needed in a <span>multicellular organism to actually obtain oxygen and give out carbon dioxide. Without this ventilation system, it would be very difficult for multicellular organisms to survive. It has been also observed that surface diffusion is not enough for a multicellular organism to breath.</span>
Ocean currents can be found both on the ocean surface and in deep water below 300 meters (984 feet). Surface currents are driven mainly by wind, but sometimes they can be driven by other things such as the movement of animals ect. While the Deep current are while the deep ocean currents are driven by density and temperature gradients. Thermohaline circulation is also known as the ocean's conveyor belt (which refers to deep ocean density-driven ocean basin currents). These currents, called submarine rivers, flow under the surface of the ocean and are hidden from immediate detection.
Sorry wasn't able to answer the last two blanks
Please help me to answer my question too and I might spend more time working on your.
But my Answer Are mostly accurate
