Напишите пожалуйста и срочно почему появились корни с чередующимеся гласными.Зарание спасибо

ДАЮ 15 ПУНКТОВ!!!!!Подставьте пожалуйста слова в текст  

Write the Perfect Crime Novel

Most people are born with the natural ability to tell stories, but only a rare few have the determination to become professional authors, and even fewer have the joy of seeing their novels top the (51) ... of bestselling books. Some of the world's famous crime writers have achieved the (52) ... success of all. Who can (53) ... the appeal of famous detectives like Sherlock Holmes, Miss Marple or Hercule Poirot? Even if you haven't read the (54) ... books you will have seen them in films or on the TV.

If you have an ambition to become the (55) ... Agatha Christie what should you do? The best starting (56) ... is to read lots of examples of crime fiction written by good authors. You will need a notebook to carry around with you or, (57) ... better, some loose (58) ... of paper that you can (59) ... notes on and then file into a folder. After all, the most everyday situation – for example, watching a woman get (60) ... a train – may be the inspiration for your first bestseller.

Like any good recipe you have to know the main ingredients of a successful novel. These are: an original story, strong characters and a memorable setting.

51. 1) queue         2) list                3) row                4) line

52. 1) largest        2) greatest        3) highest          4) prime

53. 1) deny          2) refuse           3) insist              4) hide

54. 1) first            2) initial           3) early              4) original

55. 1) next           2) following     3) subsequent    4) later

56. 1) spot            2) tip                3) point              4) mark

57. 1) even           2) still               3) very               4) so

58. 1) strips          2) sheets           3) layers             4) pieces

59. 1) complete    2) do                3) fill                 4) make

60. 1) out             2) down           3) off                 4) from

карбонат магния → оксид магния + оксид углерода (4)

Что способствовало быстрому распространению покрытосеменных?