Answer:
What goes up and down without moving?
Passed from father to son and shared between brothers, its importance is unquestioned though it is used more by others.
I'm a god. I'm a planet. I measure heat.
What type of house weighs the least?
Bobby likes Jimmy but not Joe, apples but not pears, jeeps but not vans, shinny but not hockey, tennis but not squash. Who will he like, Sara or Sally?
When is it bad luck to see a black cat?