What goes up but never comes down?

(a)  

What word is pronounced the same if you take away four of its five letters?

(a)  

What has many keys but can’t open a single lock?

(a)  

I am an odd number. Take away a letter and I become EVEN – what number am I?

(a)  

What can fill a room but takes up no space?

(a)  

A red house is made of red bricks, and a yellow house is made of yellow bricks. What is a greenhouse made of?

(a)  

What begins with T, ends with T, and has T in it?

(a)  

You stare at me but I don’t blush, you switch me off when you’re in a rush.

(a)  

What can travel around the world but stays in one corner?

(a)