Both human beings and snakes have backbones, but snakes can perform more flexible movements than human beings. why?

Bones of snakes are very loosely fused together like in humans. Hence these bones can move individually allowing the snakes to be really flexible. The ribs of snakes do not join like those of humans but instead, have free ends and do not have a sternum.

i'd say that the moon rock is about 2.2 billion years old.

some fungi obtain their nutrients from a living host (plant or animal) and are called most biotrophic fungi have fairly narrow host ranges—they are specialized on a limited called rhizomorphs that allow the fungus to grow from one tree to another. ascospores are formed inside a sac-like structure called an ascus. so your answer is a