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.