XI

1, with

2, to

3, up

4, out

5, on

6, for

7, on

8, into

9, off

10, for

XII

1, turn

2, electricity

3, gasoline

4, conserve

5, new

6, recycled

7, cardboard

8, hard

XIII

1, Coal is more expensive and more polluting than natural gas.

2, We are looking for cheap and clean and effective source of energy.

3, Will fossil fuels be replaced with solar and wind within 20 years?

4, I have visited Yaly hydroelectric power plant once before.

5, The first hydroelectric power plant was built in Niagara Falls in 1879.

6, You should switch off electrical appliances when they aren’t in use.

7, Despite being the most polluting of fossil fuels, coal is still the largest sources of energy worldwide.

8, People will use biogas for fuel in homes and for transport.

Chúc bạn học tốt!