n. a piece of land shaped like a triangle that is formed when a river splits into smaller rivers before it flows into an ocean
The archeologists found many ancient materials in the delta of the Nile River.

v. to turn or cause someone or something to turn around repeatedly
Players hold the rope and spin the fish above their heads.

v. to move upward
The airplane rises in the sky.

n. a natural power or effect that is able to change the speed or direction of something
It did not do so with the amount of force that was required.

n. the regular upward and downward movement of the level of the Earth‘s oceans that is caused by the pull of the Sun and the Moon
The tides are heavily influenced by the position and proximity of the moon.

n. someone or something that is completely different from someone or something else
She did the exact opposite of what I asked her to do.

v. to become lower
The rain is falling down harder.

n. the curved path that something follows as it goes around something else
All the planets in space are constantly in orbit.

n. a set of events or actions that happen again and again in the same order
The plant cycle of making flowers and seeds and then more plants is important to all of us.

n. the natural force that causes objects to move toward each other
Without gravity, we would all be floating in the air.