The innate immune system comprises all of the following EXCEPT: A. The mucous membranes, which produce mucus that traps germs and carries them away.
B. Mast cells, which produce an inflammatory response to suspicious objects by releasing signaling molecules.
C. Antihistamines, which are responsible for helping to reduce our body's reaction to allergens.
D. Leukocytes, which can easily travel through the circulatory system to respond to infections.

answer: - few nutrients

high pressure

low temperatures

explanation: 1. few nutrients:   open-ocean zone is located way far from the land, which is the main source of the essential nutrients.2. high pressure: pressure increases by 1 atmosphere for every 10 meters increase in depth.3. ample sunlight: a large fraction of the sunlight is reflected back to the atmosphere from the sea surface. 4. varying salinity: below the thermocline, the water is isolated from the atmosphere so the salinity remains stable over the year.5. low temperatures:   the temperature of open-ocean zone ranges from a low of -2°c to an average of 17°c

links? do you have a link? i don't see anything?