Andrew Walton. Yes, that was the man's name. Obviously. He just said that. Pay no attention to grumpy Adi, folks. Waking up late and having to hurry to classes without breakfast did not go well with him. In any case, it was no one's fault but his own.

Anything about plants? Sure, Professor. Adi was just about to raise his hand but he stopped short when he noticed Angel was...crying? What's wrong with his little sister? He immediately forgot his bad mood as he leaned towards her and whispered, "Are you okay?'' Well, she wasn't but he couldn't speak more. Not when class was on.

Anyway, onto the question. The boy thrust his hand in the air. "They produce oxygen that is needed to sustain humans and animals.'' Eyes back to Angel. He was concerned. Yes.