31. a number of, the number of

a number of許多，謂語動詞用復數(shù)。the number of…的數(shù)目，謂語動詞用單數(shù)。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(nèi)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?nèi)齻�（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, take the air

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

41. in a word, in words

in a word總之，一句話， in words口頭上 in a word, you are right.

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.

43. in secret, in the secret

in secret秘密地，暗自地，偷偷地，一般用作狀語；in the secret知道內(nèi)情，知道秘密，一般用作表語 my mother was in the secret from the beginning.

44. a girl, one girl

a girl可泛指所有女孩, one girl一個女孩 can one girl carry such a big box?

45. take a chair, take the chair

take a chair相當于sit down坐下，take the chair開始開會