石头讲词：plunge [plʌndʒ] n. 投入;跳进 vi. 投入;陷入;跳进 vt. 使陷入;使投入;plunge into 跳进; 纵身投入; 同义词：n. 投入;跳进 investment, input n. 投入;陷入;跳进 plough into, throw one's self into n. 使陷入;使投入;使插入 let sb in for, let in for