Answer:
A.
Explanation:
All of the elements in a period have the same number of valence
electrons.
<span>B. Marsupials. </span>Amniotic eggs is a unique kind of egg because they possess a semipermeable shell to protect the egg but it also allows gas exchange. Inside an amniotic egg contains the amnion, chorion and allantois. Animals that lay amniotic eggs are called amniotes, which include reptiles, birds, dinosaurs, monotremes (platypus).
When all the members of a species disappears, this is called extinction.
-hope this helps :3
<span>These three adaptations make sure of the success of prokaryotes.
It is fast reproduction make organisms to out-compete other organisms by sheer
numbers then asexual reproduction give way to the organism to take no risk in
change if the environment is constant and Cell walls help prokaryotes resist
harsh conditions.</span>