Letter D: The amount of sleep a student gets affects student achievement
-I believe the star gives off energy-, With<span> most </span>stars<span>, like our sun, hydrogen </span>is<span> being converted into Helium, a process which gives </span>off<span> energy that heats the </span>star<span>.</span>
The yo-yo speeds up when you rub it
(3) The frictional force exerted by the floor on the box
