If we (21) ___to eco-friendly options like electric vehicles, bicycles or public transport, our city will have cleaner air and a brighter future. A switch B switched C had switched D would switch

1_____energy were difficult to harness, we would be able to produce lots of clean energy. A If B As long as C Unless D On condition that

Renewable energy sources can’t be ______in the natural world. A polluted B depleted C predictable D impactful

A viable B impactful C permanent D usable

(22)_____make a change together for a healthier, more sustainable city. A Why don’t B How about C Shall we D Let’s

A pollute B reduce C commute D excuse

A mode B town C home D growth

Unless we _____ a suitable location for wind energy, we won’t be able to build wind turbines. A find B don’t find C found D didn’t find

19 If I were you, I ______ down on my daily use of fossil fuels from now on. A will cut B would cut C would have cut D could have cut

A investment B energy C depletion D benefit

The Sun Travel’s revolutionary solar panels (21)____the solar power, providing you with unlimited energy. A. produce B. maintain C. harness D. promote

(22)_____ fuel-powered cars had never been invented, this is what we would be driving! A. If B. Unless C. When D. While

16 Some types of green energy sources are very difficult to be in some nations. A harnessed B impacted C reduced D contributed