Question

1. the tides are caused by...

the moons gravity.
earths gravity.
the lack of gravity on the sun.
the lack of gravity on the moon.

Explanation:

Tides are mainly caused by the gravitational pull of the moon on Earth's oceans. Earth's gravity keeps us on the ground and is not the cause of tides. The sun has gravity and it also affects tides (less than the moon), but the statement about lack of gravity on the sun or moon is incorrect.

Answer:

the moon's gravity.