Answer:
MT_TF_S What are the missing letters? Why?
Up on high I wave away but not a word can I say.
If you drive on this, pedestrians and the police will be pretty upset with you.
It comes from crystal and melts to a treat. Add it to your tea to make it sweet. What is it?
What flies forever, rests never?
I touch the Earth, I touch the sky, but if I touch you, you’ll likely die. What am I?