What institution are this?

The valve seat performs two functions: it provides a seal for the valve in the combustion chamber, and it provides a cool surface to carry heat away from the valve. most valves use a seating angle.

Which is a type of tectonic plate boundary?

Why is the road most slick when it first begins to rain? a. oils the road has absorbed begin to float. b. the water has not had time to run off. c. a higher concentration of dirt makes the road more slick. d. none of the above