About Sound

1.What is the difference between elastic modulus and bulk modulus?
2.What is the difference between stiffness and bulk modulus?Are they same?
3.The speed of longitudinal wave in solid are depend on what?
4.The speed of longitudinal wave in fluid are depend on what?
5.Does liquid has stiffness?
6.Wikipedia:The speed of sound in substances depends on the stiffness and bulk modulus of substances.Why?

Please tell me!!Thank you!

Can anybody help me?

~James~,
you need to put your questions in ways that can be understood.

5. For example, surely should read, 'Does liquid have stiffness?' Am I being right?

6. Makes not much sense. I'm not sure what you were trying to ask.

Steve