22.
C) Hydroelectric plants put dirty water back into the environment.
23.
B) can kill aquatic life when they are thrown into the water.
24.
D) A and B (I think both of them mean the same)
25. Tag question: You didn't tell Sue about the surprise party, ....?
A) Did you?
26. Tag question: Nobody had a good time during the quarantine, ...?
C) Did they?
27. First conditional: He will never speak to me again if he finds out what's happened.
B) finds
28. Did you registered (register) for the Online English Olympiad held by Dadakhanov? he asked.
Reported speech: He asked me if I had registered for the Online English Olympiad held by Dadakhanov