At the elbow joint, two bones meet. There is a cavity between the bones and cartilage covers the
ends of each bone for protection. What type of
joint is it?
fixed
synovial
synarthrosis
cartilaginous

 synovial

Explanation:   relating to or denoting a type of joint which is surrounded by a thick flexible membrane forming a sac into which is secreted a viscous fluid that lubricates the joint.

"synovial fluid"

i believe the answer would be 'd'.

hope this !

answer; /// i believe its the cochlea;