Answer:
nitrogen that cannot be used
A parasite moving between individuals other than parents and their offspring uses
horizontal transmission.
Horizontal transmission is the transmission of infections between (parasites) that are not in a parent-child relationship (vertical transmission). Horizontal transmission may include the carriers or <span>vectors which are other species. Transmission, in that case, occurs via the bite of the vector (an infected organism), like in malaria.</span>
We have seasons because the earth is tilted as it makes its way around the sun. So its always pointed in one way at the sun, causing different asmophere as we go around the sun.
I Believe The Answer Is B. Physical Weathering.