43. We’ll visit Europe next year ________ we have enough money.
A) lest B) until C) unless D) provided

44. These two areas are similar ________ they both have a high rainfall during this season.
A) to that B) besides that C) in that D) except that

45. ________ the calculation is right, scientists can never be sure that they have included all variables and modeled them accurately.
A) Even if B) C) If only D) So long as

46. Excuse me. If your call’s not too urgent, do you mind ________ mine first?
A) I make B) if I make C) me to make D) that I make

47. We need a chairman ________.
A) for whom everyone has confidence B) in whom everyone has confidence
C) who everyone has confidence of D) whom everyone has confidence on

48. The British are not so familiar with different cultures and other ways of doing things, ________ is often the case in other countries.
A) as B) what C) so D) that

49. Criticism and self-criticism is necessary ________ it helps us to find and correct our mistakes.
A) by that B) at that C) on that D) in that

50. The minister was the person _______ honor the state dinner was given.
A) whom the state dinner was given in honour B) for whom the state dinner was given honour
C) whose honour the state dinner was given D) in whose honour the state dinner was given

51. An investigation was made into the accident, _______ fifty people were killed.
A) for that B) where C) when D) in which

52. ________ you are familiar with the author’s ideas, try reading all the sections as quickly as you possibly can.
A) As long as B) Ever since C) So that D) Now that

53. The time is not far away ________ modern communications will become widespread in China’s vast countryside.
A) when B) as C) until D) before

54. The students will put off the outing until next week, ________ they won’t be so busy.
A) when B) as C) since D) while

55. I have not found