B.
The cynobacteria were already there without the oxygen, so that rules out A, and a lot of prokaryotes were anaerobic, so that rules out C. Finally, Photosynthesis does not require oxygen. Instead, Oxygen is a waste product of it. Therefore, it cannot be D. So, we are only left with B
Hoped this helped :D
The correct answer is hydrogen<span>, and </span>oxygen<span>. </span>
Animal fibers are fibers from animals and consist mainly of protein. They contain not only silk fiber from silkworms and fur fiber from sheep wool but also collagen fiber extracted from animal skins, chitin from crustaceans, and shellfish like shrimp and chitosan made by deacetylating chitin.
i. When an acid reacts with metal, a salt and hydrogen are produced:
ii. When oxygen and metal react, metal oxide forms also known as rust
iii. Acid and water produce hydroxide ions
Answer:
A disease caused by a plasmodium parasite, transmitted by the bite of infected mosquitoes.
The severity of malaria varies based on the species of plasmodium.
Symptoms are chills, fever, and sweating, usually occurring a few weeks after being bitten.
People traveling to areas where malaria is common typically take protective drugs before, during, and after their trip. Treatment includes antimalarial drugs.
Explanation: