Answer:
I am a room that has a roof but no walls. What am I?
I am a pretty one, fluttering in the pale blue sky. Delicate, fragile on the wing, indeed I am a pretty thing. What am I?
When it comes to me, you go on red and stops on green. What am I?
I'm light as a feather yet the strongest person can't hold me for more than a few minutes. What am I?
I am flora, not fauna. I am foliage, not trees. I am shrubbery, not grass. What am I?
What made Cyclops quit teaching?