50. Someone had invented electric lights before I was born. ……………………………………………………………………………………………………. 51. Before they took exams they had revised their lessons. …………………………………………………………………………………………………… 52. When he came home his father was reading a newspaper. …………………………………………………………………………………………………… 53. My father will take me to Ho Chi Minh City next week. ………………………………………………………………………………………………….. 54. When I was 18 years old, my parents allowed me to go out in the evening. …………………………………………………………………………………………………… 55. You were wearing your new hat when I met you yesterday. …………………………………………………………………………………………………… 56. He is preparing everything for the presidential election. …………………………………………………………………………………………………… 57. Last Friday, when I came to Jane’s house, she had finished all exercises. …………………………………………………………………………………………………… 58. Countries are finding a way to solve the problem. …………………………………………………………………………………………………… 59. He put the letter in the drawer, and then he locked it up. …………………………………………………………………………………………………… 60. By the end of this year, we will have learnt 2,000 English words. …………………………………………………………………………………………………… 61. Her father was planting different kinds of flowers in the garden. …………………………………………………………………………………………………… 62. The Prime Minister is making a speech at the moment. …………………………………………………………………………………………………… 63. The doctor pulled out one of my teeth yesterday morning. …………………………………………………………………………………………………… 64. His wife usually brings him sandwiches at lunch time. …………………………………………………………………………………………………… 65. The light went out while I was making a cup of tea. …………………………………………………………………………………………………… 66. When she went to Barcelona, she learnt some Spanish. …………………………………………………………………………………………………… 67. The students of chemistry made many experiments last week. …………………………………………………………………………………………………… 68. For the past years, I have done all my washing by hand. ……………………………………………………………………………………………………