Why do we preferably have round manhole covers and not square ones?

If you drop me I’m sure to crack, but give me a smile and I’ll always smile back. What am I?

John was piloting a plane behind a car but was never able to overtake it. Why?

A mathematician couple was having a Frappuccino in Starbucks sitting opposite to each other. Suddenly the guy noticed the text written on the paper in front of them and exclaimed that it was wrong. The girl denied it and said it is appropriate. Both are correct. What is written on the paper?

What has lots of eyes, but can’t see?

Teacher ask the student

'Why are you standing on that chair in music class ?'.

what did student replied ?

Divide 110 into two parts so that one will be 150 per cent of the other. What are the 2 numbers?

Speaking of rivers, a man calls his dog from the opposite side of the river. The dog crosses the river without getting wet, and without using a bridge or boat. How?

They do not possess flesh or feathers or scales or bone
But still, they are blessed with fingers and thumbs of their own.

Four children having five rocks each were playing a game in which they had to throw the rock at a particular solid area in the water. Child 1- Succeeded in throwing three rocks at a solid area but one of the rocks sunk. Child 3 - His aim was so bad that all rocks got sunk. Child 4- He was awesome and none of the rocks got sunk. Child 2 - Was the winner but was struck by a rock in the head and died. Who killed Child 2?