D. Learned behaviors do not directly affect natural selection because they are not inherited.
This is true because learned behaviors can be taught to the offspring but do not come within them the way instincts do.
B is correct. Krypton is a noble gas which has a full outer shell of 8 electrons and is generally unreactive because of it.
Answer:
Ventilation and mixing outdoor air with indoor air
Explanation:
It uses unicellular cells.
