Answer:
Cilia, tail-like projections found on the surface of cells, are perhaps best known as molecular flippers that help cells move around. ... Cilia, tail-like projections found on the surface of cells, are perhaps best known as molecular flippers that help cells move around.
I think it’s C explanation : i learned this a while ago
The answer is D
One way to remember this is when you are building a bridge there is one piece right in the middle that keeps the whole thing from collapsing that is called the key-stone. If a keystone species goes extinct then the rest of the ecosystem will crumble around it.
Oil, coal, natural gas, metals, stone and sand are natural resources. Other natural resources are air, sunlight, soil and water. Animals, birds, fish and plants are natural resources as well.
