46. go to sea, by sea, by the sea
go to sea當海員，出航，by sea乘船，由海路， by the sea在海邊 go by sea
47. the doctor and teacher, the doctor and the teacher
the doctor and teacher指一個人，既是醫生又是老師，the doctor and the teacher兩個人，一個醫生和一個老師 the doctor and teacher is
48. in office, in the office
in office在職的，in the office在辦公室里 he is in office, not out of office.
49. in bed, on the bed
in bed臥在床上，on the bed在床上 the book is on the bed. he is ill in bed
50. in charge of, in the charge of
in charge of管理，負責照料， in the charge of由……照料 he is in charge of the matter. the matter is in the charge of her.
51. in class, in the class
in class在課上，in the class在班級里 he is the best student in the class.
52. on fire, on the fire
on fire著火,on the fire在火上 put the food on the fire. the house is on fire.
53. out of question, out of the question
out of question毫無疑問的，out of the question不可能的
54. a second, the second
a second又一，再一，the second第…… he won the second prize.
55. by day, by the day
by day白天，by the day按天計算 the workers are paid by the day.
56. the people, a people
the people指人，a people指民族 the chinese is a peace-loving people.
57. it, one
it同一物體，one同類不同一 i lost my pen. i have to buy a new one.
58. that, this
that指代上文所提到的，this導出下文所要說的 i was ill. that's why…
59. none, nothing, no one
none強調有多少，nothing, no one強調有沒有，nothing指物，no one指人--- how many…/how much…? --- none.
60. anyone, any one
anyone指人，不能接of，any one指人物均可，可接of any one of you