Riddles to strengthen the mind

The more you take the more you leave behind, What am I?

What belongs to you, yet others use it more than you?

Marys' father has three children: April, May and ...

What starts with T, ends with T, and has T in it?

I make two people out of 1, What am I?

What is more useful when it is broken?

They don't have flesh or feathers, or scales or bone, yet they have fingers and thumbs of their own. What are they?

Before Mount Everest was discovered, what was the tallest mountain in the world?

I am 24 and my brother is half my age, how old will he be when I am 70?

I have cities but no houses, mountains but no trees and water but no fish. What am I?