Since no one got the 2nd meaning of my third riddle, im saying it now so you cant answer later. Its closed
2nd Meaning; Look in the mirror, see what you SAW, use the saw to cut the table in half, two halves make a (w)hole, go through the hole. Its a play on words

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#4 (I made this one up just now)
Seen from above, Im wavy-looking. Seen from within, Its dark. If you tried to breathe in it, you'd choke. What two things am I?