48. To our s______________ ,they made great progress in their studies.
47. After the passengers had gone on board, the ship set s_____________ for New York.
46. At the sound of the bell, the pupils r____________ out of the classroom.
45. The ancient castle(城堡) has fallen into r__________ over the last two hundred years.
44. It’s bad manners to be r______________ to others.
43. Don’t throw r ______________ everywhere, you should keep it clean and tidy.
42. The soldiers are standing in r____________.
41. The paper feels r____________ ;it isn’t smooth at all.
40. The wheel of history keeps r________________ on.
39. Computers play an important r_____________ in our life.