v. to find out who someone is or what something is
To solve a problem, we need to identify the cause of the problem.

n. the upper layer of an area of land or water
This stone has a smooth surface.

n. an area of moving water that is raised above the other parts of the water of an ocean, a lake, etc.
The water was filled with large blue waves.

v. to look at something in order to make sure that it is right or correct, or that there is nothing wrong with it
The doctor checked the boy's wrist after he fell off a bike.

n. person whose job is to protect swimmers
One lifeguard saved on my life when I fell into the swimming pool.

v. to point out, show, or be a sign or symptom of
The man indicated he felt sick before leaving the party.

adj. existing or happening now
DNA is present in every cell of the body.

n. a continuous movement of water or air in the same direction
Ocean currents come from many different places.

v. to ride on ocean waves using a special board
She learned to surf last year.

adj. unable to be done or to happen
Some people want to live forever but it is impossible to do.