今天我们要学的词是step in. To step in 有插手，干预的意思。Federal health officials stepped in to help to contain the outbreak after more than 250 people fell ill to a rare parasite. 一种罕见的寄生虫让250多人病倒后，美国联邦健康部门官员出面协助控制疫情。美国汽车城市底特律申请破产保护后，The White House promised to work with city leaders but stopped short of committing to step in and bail the city out. 白宫保证跟底特律市的领导人共同努力，但是没有保证要由联邦政府出面救助底特律。好的，今天我们学习的词是step in, step in, step in...