Police frogmen have been searching the lake looking for a weapon.警方的蛙人一直在湖中寻找一件凶器。Yesterday police frogmen dragged a small pond on the Common.昨天警方的潜水员用拖网探查了一个公地小池塘的池底。These soldiers have to undergo very rigorous trainings before they become frogmen.这些兵在成为蛙人之前都必须经过非常严峻的训练。