Answer:
D.)
Explanation:
The periodic table is divided into vertical periods and horizontal groups.
If there is no antigen the blood group is 0 !!
extra info ; if both antigen - AB
A because studied it already
It is called as conservation biology. Conservation biology
aims to protect species, their habitats and the ecosystem from extinction. It is
one field of ecology that focuses on the environmental problems caused by
humans. It aims to reverse and understand the cause of loss of biodiversity.
Answer: A
Explanation:
Oxygen makes up another 20 to 21 percent of our atmosphere. It's essential for life on Earth, and interestingly enough, it is poisonous when highly concentrated. Our concentration of 20 to 21 percent seems just right.
