To occur, nuclear fusion requires extremely high _____.
velocity
pressures
temperatures
explosives

fusion needs to force molecule togetherthey also need to move fast enough to colide (tempureature) there is a minimum tempurature of 18,000,000 F or 9999982.2222 celcius or I would say pressure and tempurature, but I would choose pressure because this extremem pressure could make the requiared tempureature