Benchmark 4B
The Physical Setting: The Earth
Grades 6-8, page 69

Everything on or anywhere near the earth is pulled toward the earth's center by gravitational force.

NSES Content Standard D
Earth and Space Science: Earth in the Solar System 
Grades 5-8, page 161 
Gravity is the force that keeps planets in orbit around the sun and governs the rest of the motion in the solar system. Gravity alone holds us to the earth's surface and explains the phenomena of the tides.