when/while引导的时间状语从句 — 英语填空题
题目
根据句意，用 when 或 while 填空（每空一词）：(1) ___ the ground suddenly started to shake, people in the building ran out quickly. (2) The volunteers kept handing out food ___ the rain kept falling. (3) I was reading by candlelight ___ the lights suddenly came back on.