16. speech, talk, lecture
speech指在公共場所所做的經過準備的較正式的演說，talk日常生活中的一般的談話，講話，lecture學術性的演講，講課 a series of lecture on…
17. officer, official
officer部隊的軍官，official說什麼官員 an army officer
18. work, job
二者均指工作。work不可數，job可數 a good job, many jobs
19. couple, pair
couple主要指人或動物，pair多指由兩部分組成的東西 a pair of trousers
20. country, nation, state, land
country側重指版圖，疆域，nation指人民，國民，民族，state側重指說什麼，政體，land國土，國家 the whole nation was sad at the news.
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複數形式, 賠償金 $900 damages
23. police, policeman
police警察的總稱，後接複數謂語動詞，policeman 指某個具體的警察 the police are questioning everyone in the house.
24. problem, question
problem常和困難連繫，前面的動詞常為think about, solve, raise，question常和疑問連繫，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多指戶外的遊戲或娛樂活動，如打球，游泳，打獵，賽馬等；game指決定勝負的遊戲，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.