数字: numeral, digit, number, figure, amount, digital (electronics etc)...
核武器: nuclear weapon...
环绕: to surround, to circle, to revolve around...
队长: captain, team leader...
好听: pleasant to hear...
寒暄: to exchange conventional greetings, to exchange pleasantries...
绿灯: green light (traffic signal), permission to proceed...
内在: inner, internal, intrinsic, innate...
归还: to return sth, to revert...
积蓄: to save, to put aside, savings...