The earthquake of 26th December 2004 resulted in one of the worst natural disasters in living memory. It was a (31) ___A__ underwater quake and occurred in the Indian Ocean. It (32) __C__ coastlines, communities and brought death to many people.

Why do earthquakes happen?

The surface of the earth has not always looked as it does today; it is moving (33)__D__ (although very slowly)and has done so for billions of years. This is one (34)__B__ of earthquakes, when one section of the earth (tectonic plate) (35)__A__ another. Scientists can predict where but not (36)__C__ this might happen and the area between plates is called a fault line. On one fault line in Kobe, Japan in 1923 over 200,000 people were killed.(37)__B__, earthquakes do not always happen on fault lines, (38)__A__ is why they are so dangerous and (39)__D__.

Where do volcanoes happen?

Volcanoes happen where the earth’s (40)__C__ is thin: lava, dust and gases (41)__A__ from beneath the earth. They can rise into a huge cone shape like a mountain and erupt, (42)__B__ they can be so violent(43)__D__ they just explode directly from the earth with no warning. There are 1511(44) ‘__C__’ volcanoes in the world. This means that they may (45)__B__ be dangerous. In 1985 the Colombian volcano Nevado del Ruiz erupted. The lava melted a glacier and sent tones of mud (46)__D__ the town below. Twenty thousand people died. Natural disasters like volcanic eruptions are often unpredictable. We regularly do not know when they (47)__A__ pen，or (48)__C__ where they will happen. In the future，scientists may be able to watch and predict (49)__D__ before they happen. This could (50)__B__ many lives.

31. A. massive B. significant C. great D. grand

32. A. changed B. converted C. destroyed D. transformed

33. A. frequently B. periodically C. regularly D. continuously

34. A. source B. cause C. movement D. reason

35. A. collides with B. confronts with C. meets with D. faces with

36. A. how B. why C. when D. what

37. A. Generally B. However C. Similarly D. Anyway

38. A. which B. it C. this D that.

39. A. irresistible B. inevitable C. unaccountable D. unpredictable

40. A. surface B. appearance C. crust D. cover

41. A. burst out B. flowed out C. leaked out D. trickled out

42. A. and B. or C. nor D. but

43. A. like B. for C. as D. that

44. A. living B. alive C. active D. live

45. A. relatively B. still C. hardly D. gradually

46. A. beyond B. on C. across D. down

47. A. might B. should C. must D. are to

48. A. though B. whether C. even D. else

49. A. accidents B. incidents C. occasions D. events

50. A. rescue B. save C. preserve D. shelter