What's the difference between "may" and "can" ?

The difference is their tones. In a polite or formal setting, use "may" for permission.In an informal setting, it is okay to use "can" for permission

Explanation:

either a donut or a sphere or a pancake or a flat sphere. it depends on where the vertical line is.

if the line goes through the center of the circle and is perpendicular to a diameter containing the center, then you get a flat circle.

if the line and the diameter of a the circle meet in the center of the diameter and at an angle, you get a pancake.

if the line is on the circumference of the circle and is at right angles   to the circle you get a ring.

if the line contains the diameter, you get a sphere.

the the line is parallel to the diameter and touches the circumference, you get a donut.

d) sarah's natural reaction to being accepted into college suggests that she has no other dreams.