change these sentences to the passive voice
31. Mary is cutting the cupcake with a sharp knife.
32. Bad weather has delayed flight 202 from Miami.
33. They have celebrated the Teacher’s Day largely since 1982.
34. Science and Technology have completely changed human’s life.
35. People have built this building of bricks, stones and cement.
36. Nga has typed the report about polluted environment for 2 hours.
37. Brothers Lazlo and George Biro invented the ballpoint pen.
38. The boy broke the window and took away some money.
39. Someone cut down the tree in the garden yesterday.
40. The artist painted a huge pictures to raise fund for the poor children.
41. Mai wrote some articles about the damage of 11th storm.
42. Someone was making coffee while I walked into the kitchen.
43. My father was fixing the electrical sockets at this time yesterday.
44. SJC Company was holding the meeting while it began to rain.
45. Mrs. Green was mending the ladder at ten yesterday.
46. The chief engineer was instructing all the workers of the plant.
47. Mr. Han is going to visit Hanoi on his work next week.
48. This company will organize an art exhibition next mont