21. in office, in the office

　　in office在职的，in the office在办公室里 He is in office, not out of office.

　　22. in charge of, in the charge of

　　in charge of管理，负责照料， in the charge of由……照料 He is in charge of the matter. The matter is in the charge of her.

　　23. out of question, out of the question

　　out of question毫无疑问的，out of the question不可能的

　　24. a second, the second

　　a second又一，再一，the second第…… He won the second prize.

　　25. by day, by the day

　　by day白天，by the day按天计算 The workers are paid by the day.

　　26. it, one

　　it同一物体，one同类不同一 I lost my pen. I have to buy a new one.

　　27. none, nothing, no one

　　none强调有多少，nothing, no one强调有没有，nothing指物，no one指人　--- How many…/How much…? --- None.

　　28. other, another

　　other后接名词复数，another后接名词单数 other students, another student

　　29. not a little, not a bit

　　not a little非常，not a bit一点也不 I\'m not a bit tired. 我一点儿也不累。

　　30. many, much, a lot of

　　many和可数名词连用，much和不可数名词连用，a lot of可数，不可数均可，但不用于否定句 I haven't many books.

　　31. no, not

　　no=not a/any no friend=not a/any friend no water=not any water

　　32. no more than, not more than

　　no more than相当于only，仅仅，只有，not more than 至多，不超过

　　33. tall, high

　　tall常指人或动物，high常指物体 He is tall.

　　34. fast, quickly

　　fast侧重于指人或物体具有运动速度快的特点，quickly侧重指某事完成或发生的快 run fast, answer the question quickly

　　35. high, highly

　　high具体的高，highly抽象的高，高度的 think highly of

　　36. sleeping, asleep, sleepy

　　sleeping正在睡觉，asleep睡着，熟睡，只能做表语，sleepy困的，有睡意的 a sleeping baby The baby is asleep. I'm sleepy.

　　37. respectful, respectable

　　respectful尊敬，有礼貌，respectable可敬的，值得尊敬的 be respectful to the aged

　　38. pleasant, pleased, pleasing

　　pleasant常用作定语，pleased, pleasing常用作表语，pleased主语常为人，pleasing主语常为物 a pleasant trip The trip is pleasing.

　　39. close, closely

　　close接近，靠近，closely紧紧地，紧密地 closely connected, stand close

　　40. ill, sick

　　ill做表语，sick定，表均可 a sick boy