Directions: There are 30 incomplete sentences in this part. For each sentence there are four choices marked A), B), C) and D). Choose the ONE answer that best completes the sentence. Then mark the corresponding letter on the Answer Sheet with a single line through the centre.

　　31. This is not an economical way to get more water; ________, it is very expensive.

　　A) or else

　　B) in short

　　C) on the contrary

　　D) on the other hand

　　32. First published in 1927, the charts remain an ________ source for researchers.

　　A) intelligent B) indispensable

　　C) inevitable D) identical

　　33. You should try to ________ your ambition and be more realistic.

　　A) restrain B) retain

　　C) reserve D) replace

　　34. There is a ________ of impatience in the tone of his voice.

　　A) dot B) hint C) notion D) phrase

　　35. Deserts and high mountains have always been a ________ to the movement of people from place to place.

　　A) jam B) barrier

　　C) fence D) prevention

　　36. Joe is not good at sports, but when it ________ mathematics, he is the best in the class.

　　A) comes up to B) comes around to

　　C) comes to D) comes on to

　　37. Please ________ dictionaries when you are not sure of word spelling or meaning.

　　A) search B) seek

　　C) inquire D) consult

　　38. Critics believe that the control of television by mass advertising has ________ the quality of the programs.

　　A) affected B) effected

　　C) lessened D) declined