Выпишите из каждого предложения глагол – сказуемое и определите его видовременную форму и залог. Напишите форму инфинитива глагола.
1. Mankind has used coal and oil in gradually increasing quantities for centuries. 2.The consumption of energy is expected to grow so new resources should be found.
3. Electric heaters play a large part in the air conditioning plants of large buildings.
4. Heating is used to provide comfort for people.
5. Air conditioning systems vary in cost.
6. The modern twenty–five storey hotel has been constructed in the centre of London.

1. has used - pres perf act  - to use2. is expected - pres simp pass - to expect 3. play - pres simp act  - to play 4. is used - pres simp pass - to use5. vary - pres simp act - to vary. 6. has been constructed - pres perf pass  - to construct.