21. cook，cooker cook廚師，cooker廚具He is a good cook.

22. damage，damages damage不可數名詞，損害，損失；damages復數形式，賠償金 ＄900 damages

23. police，policeman police警察的總稱，后接復數謂語動詞，policeman 指某個具體的警察The police are questioning everyone in the house.

24. problem，question problem常和困難聯系，前面的動詞常為think about，solve，raise，question常和疑問聯系，多和ask，answer連用

25. man，a man man人類，a man一個男人Man will conquer nature.

26. chick，chicken二者均可指小雞，chicken還可以當雞肉The chicken is delicious.

27. telegram，telegraph當電報解時，telegram指具體的，telegraph指抽象的a telegram，by telegraph

28. trip，journey，travel，voyage travel是最常用的，trip指短期的旅途，journey指稍長的旅途，voyage指海上航行a three-day trip

29. sport，game sport多指戶外的游戲或娛樂活動，如打球，游泳，打獵，賽馬等；game指決定勝負的游戲，通常有一套規則His favorite sport is swimming.

30. price，prize price價格，prize獎，獎品，獎金win the first prize The price is high/low.

31. a number of，the number of a number of許多，謂語動詞用復數。the number of...的數目，謂語動詞用單數。The number of students is increasing.

32. in front of，in the front of in front of范圍外的前面，in the front of范圍內的前面In the front of the room sits a boy.

33. of the day，of a day of the day每一天的，當時的，當代的，of a day暫時的，不長久的a famous scientist of the day

34. three of us，the three of us three of us我們（不止三個）中的三個，the three of us我們三個（就三個人）The three of us—Tom，Jack and I went to the cinema.

35. by bus，on the bus by bus表手段，方式，不用冠詞，on the bus表范圍They went there by bus.

36. for a moment，for the moment for a moment 片刻，一會兒，for the moment暫時，一時Thinking for a moment，he agreed.

37. next year，the next year next year將來時間狀語，the next year過去將來時間狀語He said he would go abroad the next year.

38. more than a year，more than one year more than a year一年多，more than one year超過一年（兩年或三年等）

39. take advice，take the（one's）advice take advice征求意見，take the advice接受忠告He refused to take the advice and failed again.

40. take air，傳播，走漏，take the air到戶外去，散步We take the air every day.