問題詳情:
At last firefighters have put out a big forest fire in California.Since then,they 41. (set) about finding out 42. the fire began.Forest fires are often caused by 43. (break)glass or by cigarette ends which people carelessly throw away.Yesterday the 44. (fireman)examined the ground but were not able to find any.They were also quite sure that a cigarette end didn’t start the fire.However,several hours passed 45. a fireman accidentally discovered the cause.He noticed the remains of a snake which was wound(蜿蜒;纏繞)around the electric wires of a 16,000-volt power line.In this way,he was able to solve 46. mystery.The 47.(explain) was simple but very 48. (usual).A bird had snatched up the snake from the ground and then 49. (drop)it on to the wires.The snake then wound 50. round the wires.When it did so,it sent sparks down to the ground and these immediately started a fire.
【回答】
41.have set
42.how
43.broken
44.firemen
45.before
46.the
47.explanation
48.unusual
49.dropped
50.itself
知識點:語法填空
題型:閲讀填空