51. If you study harder, you (get)_______________________ good marks in the coming examination. 52. “Harry Potter” is the most interesting film I (ever/ see)_______________________. 53. It (take)_______________________ him 2 hours every day to practice speaking English when he was a student. 54. We are all looking forward to (meet)_______________________ you. 55. Hoang Sa island district (establish)_______________________ in January, 1997. 56. Air, water and soil (be)_______________________ necessary to all living things. 57. Polluted water (kill)_______________________ fish and other marine life. 58. Robots (enter)_______________________ every day lives a long time ago. 59. In medicine, robots (use)_______________________ to replace limbs and other parts of the body. 60. Pollution (cause)_______________________ damage to air, soil and water.