what does this picture(rebus) riddle means ?

Teacher ask the student

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

what did student replied ?

Where do you go to learn how to make ice cream?

Why is the Hole below a Lock?

Three doctors said that Bill was their brother. Bill says he has no brothers. How many brothers does Bill actually have?

Which is faster, Heat or Cold ? Explain.

Count the squares in the matchstick puzzle below?

What does man love more than life, hate more than death or mortal strife; That which contented men desire; the poor have, the rich require; the miser spends, the spendthrift saves, and all men carry to their graves?

The first box has two white balls. The second box has two black balls. The third box has a white and a black ball.

Boxes are labeled but all labels are wrong!

You are allowed to open one box, pick one ball at random, see its colour and put it back into the box, without seeing the colour of the other ball.

How many such operations are necessary to correctly label the boxes?

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?