Answer:
This sparkling globe can float on water. It is light as a feather, but ten giants can't pick it up.
Without this, H2O would just be 2O
Rotten trees and Jack-O-Lanterns have this characteristic in common.
What can be measured but has no length, width or height?
What do you have in December that you don't have in any other month?
I am a room that has a roof but no walls. What am I?