Biology 101 with Professor Ramirez is the most challenging course I have ever taken. Though every inspiring class session includes exhaustive note taking and time-consuming lab work, I enjoy the material. The entertaining lectures are instructive, and all the students remain engaged throughout the hour.

Which words from the paragraph support the conclusion that Professor Ramirez is a demanding teacher? Check all that apply.

1)challenging
2)inspiring class session
3)exhaustive note taking
4)time-consuming lab work
5)entertaining lectures
6)engaged