Explanation :
Static friction is the frictional force between two objects that are at rest. While sliding friction is the frictional force between two objects in contact and are sliding w.r.t each other.
Static friction is usually greater than sliding friction because in static friction the contact forces is more and the interlocking between objects is tight as compared to sliding friction.
1. First blank is A. Conductors
Second blank is D. Insulators
2. C. Heat
The height difference is found by

Then the change in potential energy is
dissipation is the answer ;(