大学英语三级考试考前辅导练习二十三

41. How men first learnt to invent words is unknown; in other words, the origin of language is a mystery.

42. It is noise pollution that we need to control in order to help people live more happily.

43. Female smokers are thought to be less affected because they do not breathe in the smoke so deeply.

44. A paper printed in London around midnight can be at any breakfast table in England the next morning, except in remote country districts.

45. Some lighthouse in the past had to be made lower after they had been built, when it was found that the light was often hidden in the upper mists.

46. Scientists are searching for a suitable alternative, but so far in vain.

47. The government built big dams across the river and stored the water for use during the dry season when there was no rain.

48. Every human being, no matter what he is doing, givens off body heat. The problem is how to dispose of it.

49. The problem is that your study habits formed in high school may make you unable to study well in college because you have never experienced what it takes to perform at the college level.

50. Human naturally use mouth movements to help them understand differences between similar words like “bat” and “pat”.