1. sound,voice,noisesound自然界各种各样的声音，voice人的嗓音，noise噪音Ihatetheloudnoiseoutside.2. exercise,exercises,practiceexercise运动，锻炼(不可数)，exercises练习(可数)，practice(反复做的)练习takeexercise做运动3. work,job二者均指工作。work不可数，job可数agoodjob，Whatinterestingworkitis!4. cook,cookercook厨师，cooker厨具Heisagoodcook.5. police,policemanpolice警察的总称，后接复数谓语动词，policeman指某个具体的警察Thepolicearequestioningeveryoneinthehouse.6. problem,questionproblem常和困难联系，前面的动词常为thinkabout,solve,raise，quest
