THREE RHYMING RIDDLES

1)
My first is in cater, but not debater,
My second in tour, but not in sure;
My third's in small, but not in crawl,
My fourth in tomb, but not in loom.
My whole has teeth, but cannot eat,
Some may do me on the beach.

2)
I have hands that wave at you,
Though I never say good-bye;
It's cool for you to be with me,
Especially when I say "High."

3)
I come and go, twice each day,
And yet I have never once been away.

Answers:

1. COMB 
2. AN ELECTRIC FAN 
3. OCEAN