"a critical element in the approach"; "critical health care materials"; "important for any healthy society"; "of very important fascination" go critical (of the nuclear electrical power station or reactor) to succeed in a state through which a nuclear-fission chain response turns into self-sustaining engineering, finance & economics, politics specialised (of https://jaspereb60u.activablog.com/35169012/indicators-on-critical-you-should-know