Đáp án:
`1.` I will turn off the lights when leaving a room or going to bed.
`⇒` The lights will be turned off when I leave a room or go to bed.
`2.` Wind power will offer a great deal of energy next century.
`⇒` A great deal of energy will be offered by wind power.
`3.` We will use sources of energy more effectively for our future.
`⇒` Sources of energy will be used more effectively for our future.