Plzzzzz just helppp me it's 4th grade jhggguguybyubuub

Answer:
19. Ocean waves can cause rocks on a beach to erode. The water continuously splashing against them makes them change shape and slowly wear down.
20. Physical and chemical weathering are alike because they can both cause certain forms to erode. They are different because chemical weathering can form new minerals but physical just rubs away at the rock.
Explanation: