If two's company, and three's a crowd, then whats four and five ?

I have lakes with no water, mountains with no stone and cities with no buildings. What am I?

Our product and our sum always give the same answer. Who are we?

If a wheel has 54 spokes, how many spaces are there between the spokes?

I cannot talk, but I always reply when spoken to. What am I?

I came first on earth but second on the heaven.
I also came twice in a week but found just once in a year.
I stay away from months but you can find me in February.

What am I?

using four eights (8) and a one (1) and one mathematical symbol , create the number 100

Andrew sees a very rare bird named "Ruppell's vulture". Soon Andrew was dead. Can you explain the mystery, Mr. Sherlock?

I have a hole in my back and legs I lack.
I live where I can’t breathe and I eat without teeth.
What am I?

In Greek mythology, the Sphinx sat outside of Thebes and asked this riddle of all travellers who passed by. If the traveller failed to solve the riddle, then the Sphinx killed him/her. And if the traveller answered the riddle correctly, then the Sphinx would destroy herself. The riddle:

What goes on four legs in the morning, on two legs at noon, and on three legs in the evening?

Oedipus solved the riddle, and the Sphinx destroyed herself.