1.what kind of dog doesn't bite or bark?

1 .What kind of dog doesn't bite or bark?
It's a hot dog .
2.What a room has no walls,no doors,no windows,and no floors?
It's a mushroom .
3.What has hands but no feet,a face but no eyes,tells but not talk?
It's a clock .
4.What is black when it is clean and white when it is dirty?
It's a black coat.