At approximately what age should a child be able to use each hand independently?

Why does earth contain such diverse life forms?

How is the male reproductive system different from other body systems? it isn’t necessary to vital signs. it monitors other body systems, and adjusts if necessary. it transports items from one system to another. it is the only system that produces hormones in the male.

How do you date a sample of rock that you suspect as being one of the earliest on earth