Please check my answers!
1.Mr. Williams is the teacher (who, whom) went to such great trouble to help the students.
who
- Would Agnes like to swim at Holden Pond with Ellie and (I, Me)?
I
- What do you think about (his, him) being chosen as class president?
him
- Introduce the guests with (whom/whoever/who/whomever) you will be sharing ideas for the fundraiser.
whom
1.Mr. Williams is the teacher (who, whom) went to such great trouble to help the students.
who