1. Put the verbs in brackets into the correct forms of conditional type 1 or 2.

(Chia các động từ trong ngoặc thành dạng đúng của câu điều kiện loại 1 và 2.)

1. Natural resources will be depleted soon if we _____ (keep) wasting energy.

2. If the company could afford solar-powered LED lights now, they _____ (be able to cut) costs on monthly electric bills.

3. If the city _____ (build) a wind farm in this area, the residents would have access to renewable energy.

4. If we reduce the harmful effects of biomass power, the local community's health _____ (improve).

5. Unless we _____ (use) renewable energy sources instead of fossil fuels, the planet will continue to suffer. 

2. Choose the correct option. (Chọn đáp án đúng.)

1. If we _____ solar panels, we would get a supply of green energy from them.

A. install                                 B. installed     

C. had installed                       D. would install

2. _____ to LED light bulbs, we would not only save on electricity bills but also reduce our carbon footprint. A. If we switched                    B. Unless we switch

C. If we switch                        D. Unless we switched

3. If you were the mayor, how _____ our town more eco-friendly?

A. will you make                    B. had you made

C. would you make                 D. did you made

4. If we start producing tidal power, we _____ our dependence on non-renewable energy sources.

A. could reduce                       B. would reduce

C. will reduce                          D. reduce

5. We will run out of fossil fuels soon unless _____.

A. we invest in renewable energy sources.

B. we invested in renewable energy sources.

C. we don't invest in renewable energy sources.

D. we didn't invest in renewable energy sources. 

3. Rewrite the sentence using conditional type 3.

(Viết lại các câu sau dùng câu điều kiện loại 3.)

1. Susan didn't have enough money. She didn't buy that electric car.

2. They didn't invest in solar power in this area. They became reliant on fossil fuels.

3. We didn't support wind power initiatives. We didn't have access to clean energy.

4. Our country implemented energy-saving measures last year. We saved a lot of money since then.

5. Anthony didn't leave home early. He was late for the green energy workshop. 

4. Complete the sentences using the verbs in the list in the correct forms of conditionals (types 1, 2 or 3).

• switch • play • not/develop • occur • invest

1. If humans are to solve the climate crisis, using green energy sources _____ a vital role.

2. If developments in the green energy sector _____, we will find it easier to adopt green energy on a large scale.

3. Advances in battery technology would ensure a stable and reliable power supply if we _____ to green energy today.

4. Global warming _____ into such an extreme issue if we had switched to green energy earlier.

5. If we _____ in renewable energy now, we can create a brighter and more sustainable future for future generations. 

5. Choose the option (A, B, C or D) to indicate the sentence that is closest in meaning to the given one.

(Chọn đáp án (A, B, C hoặc D) để chỉ ra câu có nghĩa gần nhất với câu cho trước.)

1. I didn't know that product is bad for the environment and that's why I bought it.

A. If I had known that product was bad for the environment, I would not buy It.

B. If I had known that product was bad for the environment, I wouldn't have bought it.

C. If I knew that product was bad for the environment, I would not buy it.

D If I knew that product was bad for the environment, I wouldn't have bought it.

2. We switched to using energy-efficient appliances last month, so we reduced electricity waste a lot.

A. Unless we switch to using energy-efficient appliances, we won't reduce electricity waste a lot.

B. If we switched to using energy-efficient appliances, we would reduce electricity waste a lot.

C. If we had switched to using energy-efficient appliances, we would have reduced electricity waste a lot.

D. If we hadn't switched to using energy-efficient appliances, we wouldn't have reduced electricity waste a lot.

3. Sarah drives to work because there is no public transport available here in the village.

A. Sarah had to drive to work if there wouldn't be public transport available here in the village.

B. Sarah wouldn't drive to work if there was public transport available here in the village.

C. If there had not been public transport available here in the village, Sarah would have driven to work.

D. Sarah will drive to work unless there was public transport available here in the village.

4. Tom wants to install a solar panel at his house, but he can't afford it.

A. Tom would install solar panels at his house if he could afford it.

B. Tom will install a solar panel at his house if he could afford it.

C. Tom would have installed a solar panel at home if he could afford it.

D. Tom would install a solar panel at his house if he could have afforded it.

5. The energy crisis exists because we all rely on finite energy resources.

A. If we all had not relied on finite energy resources, the energy crisis would not have existed.

B. If we all don't rely on finite energy resources, the energy crisis will not exist.

C. Unless we all rely on finite energy resources, the energy crisis will not exist.

D. If we all did not rely on finite energy resources, the energy crisis would not exist.