Hard Riddles

I speak without a mouth and hear without ears. I have no body, but I come alive with wind. What am I? 

You measure my life in hours and I serve you by expiring. I’m quick when I’m thin and slow when I’m fat. The wind is my enemy. What am I?

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

What is seen in the middle of March and April that can’t be seen at the beginning or end of either month?

You see a boat filled with people. It has not sunk, but when you look again you don’t see a single person on the boat. Why?

What word in the English language does the following: 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? 

What English word has three consecutive double letters? 

I come from a mine and get surrounded by wood always. Everyone uses me. What am I? 

A girl has as many brothers as sisters, but each brother has only half as many brothers as sisters. How many brothers and sisters are there in the family? 

What disappears as soon as you say its name?