69. Acting has brought me some enormous ………………….. (enjoy) 70. He has had treatment for 2 months now without any ……………………… (improve) 71. You can ask that plumber for ………………on how to repair the racks in water pipes. (advise) 72. Rather ………………… researchers forecast that oil might run out in 30 years. (pessimism) 73. A complaint letter should be ended …………………… (impolite) 74. The drivers have left lots of garbage on the ground after their ………………… (refresh) 75. I think careless drivers should be fined …………………… (heavy) 76. Travelling to the countryside is becoming …………………….. popular nowadays. (increase) 77. …………………… are looking for an effective way to reduce energy consumption. (science) 78. What we must do is to keep the earth ……………………… (pollute) 79. We must use electricity ……………………… (economy) 80. ……………. energy is the best alternative source of energy. (sun)