You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

What is more useful when it is broken?

The first two letters signify a male, the first three letters signify a female, the first four letters signify a great, while the entire world signifies a great woman. What is the word?

I have no life, but I can die. What am I?

I have a clock(12-hour format) and both the needles of the clock overlap at 12:00.
After how much time, they will overlap again?

I am white when I am dirty, and black when I am clean. What am I?

Do You See It?

I am the fastest animal but cannot climb the tree. What am I?

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?

I am a five-letter word and comprises two different vowels and three same consonants. I am so strong that I can spoil your entire work.

Can you find out who am I?