Grievous give me one sentence about this ur own sentence

Grievous is a word I don't know the meaning of but should probably look up. 

Which statements describe the relationship of earth and its moon? check all that apply.the moon orbits earth following a nearly circular path.the gravitational pull of earth on the moon is parallel to the velocity of the moon.the moon orbits earth in 1 earth day.the same face of the moon always points toward earth.the moon’s orbit is the result of the interaction between the moon’s inertia and the gravitational force from earth