What causes fusion to stop within all stars?

The graph describes the motion of an object. the object moves with from a to b. it from b to c. it moves with from c to d.

Examine the equation. 23490th→23088ra+42he what kind of barrier would you need to block the radioactive particles from this reaction? a.a piece of paper b.a sheet of aluminum foil c. a two-inch block of lead d. a solid concrete block

How do we measure or think of speed in the united states?