After RdRp (RNA-dependent RNA polymerase) is synthesized, is it immediately active?

Which mantle is under the crust the upper mantle or the lower mantle i think it's upper let me know if i'm right

Iron reacts with oxygen to produce iron oxide (rust). this reaction is represented in an equation as 4fe + xo2 → 2fe2o3. identify the value of x that will balance the equation.

Aboy jumps into a cold swimming pool and his body tempature goes down hus muscles ,blood vessels