Answer:
Part carbon part water I am poison to the fishes. Many falsely claim my name I am the pause that refreshes.
I am made by nature soft as silk; A puffy cloud white as milk; Snow tops this tropical crop; The dirtiest part of a mop.
I sit in a corner while traveling around the world. What am I?
I am of several different kinds, but the one you pick doesn't do its job. What am I?
I have keys but no locks. I have space but no room. You can enter but canβt go outside. What am I?
No matter how little or how much you use me, you change me every month.