Why Aeroplane windows are round?

By removing one matchstick and adding one matchstick, can you convert the word "ZOO" to an animal name?

What goes through cities and fields, but never moves?

John was drowned by he was not wet. How?

I am a type of food that is often found in the fridge and can be white in colour. What I am?
Hint 1: I am a dairy product.
Hint 2: You can spread me on the bread.

What happened when the wheel was invented?

I have an eye but still cannot see.

Who am I?

Replace the 'X' with any mathematical symbol to make the expression equal to 111.

18 X 12 X 2 X 3 = 111

Can you make the number 24 by utilizing the numbers 1, 3, 4 and 6? You must use one number only one time and you can use mathematical operation symbols anytime anywhere.

Look at the below sequence of letters and tell us what the next letter should be:

O T T F F S S ?