48. 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.

47. the doctor and teacher, the doctor and the teacher

　the doctor and teacher指一个人，既是医生又是老师，the doctor and the teacher两个人，一个医生和一个老师the doctor and teacher is

46. go to sea, by sea, by the sea

　go to sea当海员，出航，by sea乘船，由海路， by the sea在海边go by sea

45. take a chair, take the chair

　take a chair相当于sit down坐下，take the chair开始开会

44. a girl, one girl

　a girl可泛指所有女孩, one girl一个女孩Can one girl carry such a big box?

43. in secret, in the secret

　in secret秘密地，暗自地，偷偷地，一般用作状语；in the secret知道内情，知道秘密，一般用作表语My mother was in the secret from the beginning.

42. in place of, in the place of

　in place of代替，in the place of在…地方A new building is built in the place of the old one.

41. in a word, in words

　in a word总之，一句话， in words口头上In a word, you are right.

40. take air, take the air

　take air传播，走漏，take the air到户外去，散步We take the air every day.

39. take advice, take the(one’s) advice

　take advice征求意见，take the advice接受忠告He refused to take the advice and failed again.