46.The countryside is most beautiful in autumn. (Cleft Sentence)

47.It is Tet that is celebrated as the greatest occasion in a year by Vietnamese people.

48.The teacher was asked for his explanation for the problem by the students

49.Nam was prevented from going to school by the thick fog

50.They think that I should do volunteer work

51.We must do well at school

52.These instructions could be understood by anyone with the smallest intelligence

53.This rumor must have been started by our opponents 

54. You mustn't use your cell phone in class

55.Tom should see the doctor because of his terrible cough

chúc học giỏi46.The countryside is most beautiful in autumn.
47.It is Tet that is celebrated as the greatest occasion in a year by Vietnamese people.
48.The teacher was asked for his explanation for the problem by the students49.Nam was prevented from going to school by the thick fog

50.They think that I should do volunteer work

51.We must do well at school

52.These instructions could be understood by anyone with the smallest intelligence

53.This rumor must have been started by our opponents 

54. You mustn't use your cell phone in class

55.Tom should see the doctor because of his terrible cough