The first box is a dangling modifier. The second is a clause. The last is a phrase. (Answers going from top to bottom) :)
4) Time-consuming lab work
3) Exhaustive note taking
It's asking you proof that Ramirez is a demanding teacher not about the course itself so it is not 1, 2, 4 or 6. It is 4 and 3 because it shows Ramirez was demanding by enforcing a heavy load of work
Answer: the answer is C
Explanation: a public domain is when its public and has no official copyright so anyone can use it