Answer:
There needs to be enough sea urchins for otters to come and there needs to be enough otters to eat the urchins.
Explanation:
One reason is if someone is injured and needed to use pain pills, sometimes they get addicted to it
The answer is B . two atoms exchange electrons and become ions
Through my research I found matching questions with similar answers:
A) macrophages
B) antigens
C) antibodies
D) lymph
The best answer to fill in the blank would be the third option C) Antibodies which in the name anti means against, so since the word anti is the same as against, its a battle between antibodies and invaders, so that's why its C).
