Fossils are the remains or impression of the dead animals and plants that lived in the past.
Answer:
4
Explanation:
Carbon has four valence electrons, so it can achieve a full outer energy level by forming four covalent bonds. When it bonds only with hydrogen, it forms compounds called hydrocarbons. Carbon can form single, double, or triple covalent bonds with other carbon atoms.
Answer:
B. Polio
Explanation:
The poliovirus causes brain damage (resulting in paralysis) and muscle degeneration. You're welcome.
Answer:
Eutrophication
Explanation:
When a body water lies in close proximity to any agricultural land, there are high chance of it receiving nutrient from the surrounding land in rainy season. The rich nutrient run off from these land parcels, mixes with the water of existing water body and make it extremely rich in growth nutrients. The excess of nutrients causes uninterrupted growth of algae and lead to algal boom. Oxygen in such water bodies depletes at a fast rate due to the increased productivity thereby harming the water animals living in it.