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

O_er_t_o_

Complete the missing letters of the given word.

A certain street contains 100 buildings. They are numbered from 1 to 100. How many 9's are used in these numbers?

This is a most unusual paragraph. How quickly can you find out what is so unusual about it? It looks so ordinary, you'd think nothing was wrong with it. Actually, nothing IS wrong with it. But it is not as ordinary as you might think. If you think about it for a bit, you will find out why it is truly so unusual. So what is it? What is so unordinary about this paragraph?

What breaks yet never falls, and what falls yet never breaks?

How can you write nineteen in a manner that if we take out one, it becomes twenty?

The more you take me, the more you leave me behind.
Who Am I?

Can you name three consecutive days without using the words Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, or Sunday?

Can you name any English verb that becomes its past tense by simply rearranging the alphabets ?

Two in a corner, one in a room, zero in a house, but one in a shelter. What is it?