The engine keeps backfiring all the time.發(fā)動(dòng)機(jī)老是回火.The EPA's rules about what constitutes hazardous waste are backfiring against the nationwide recycling effort.環(huán)保署關(guān)于有害物質(zhì)的法規(guī)同全國(guó)資源回收的工作正好唱反調(diào).A sudden report rang out -- ...