The following sentences all use pronouns correctly
joseph said that he was angry when he was left at the school all alone
i knew it was she who made the mistake
sammy knew that her mother would be happy about the report card, and her mother would probably smile.
true
false

The sentences use relative pronouns correctly to introduce relative clauses.

Explanation:

The pronouns which are repeated are THAT and WHO. Both of them are used to give more information about people or things.

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.