Riddle: I only have two backbones and thousands of ribs. What am I?
Answer: A railroad.
Riddle: I have legs but walk not, a strong back but work not, two good arms but reach not, a seat but sit and tarry not. What am I?
Answer: An Armchair.
Riddle: Soldiers line up spaced with pride, Two long rows lined side by side. One sole unit can decide If the rows will unite or divide. Tell me, tell me, scream it out. What's the thing I talk about?
Answer: A zipper.
Logic Puzzles
Riddle: I am cold to the touch but yet I burn if held. What am I?
Answer: I am dry ice. Dry ice is frozen, solid, carbon dioxide that freezes at −109.2F.  The extreme cold makes it dangerous to handle with bare skin.
Riddle: I come in different shapes and sizes. Parts of me are curved, others are straight. You can put me anywhere you like, but there is only one right place for me. What am I?
Answer: Jigsaw puzzle pieces.
Logic Puzzles
Riddle: bcdfgh__?
Answer: J (this is a sequential list of consonants).
Riddle: From house to house I go, sometimes narrow, sometimes wide. And whether there's rain or snow I always stay outside. What am I?
Answer: A Path.
Logic Puzzles
Riddle: You are sitting at a table eating lunch and there are ten flies on the table. With a quick swat, you are able to kill three flies. How many flies are left on the table?
Answer: You killed three flies which remain on the table.  The others flew off when you swatted.
Riddle: I always point in the right direction. My instructions are written in black and white. Disobey me and pay the consequences. I will never say more than two words at a time. What am I?
Answer: A "One Way" sign!
Riddle: I welcome the day with a show of light, I stealthily came here in the night. I bathe the earthy stuff at dawn, But by noon, alas! I'm gone. What am I?
Answer: The morning dew!