Unit 6: Looking back
1. Listen and repeat the questions paying attention to the rising intonation. 

1. Do you know that global warming is increasing?
2. Did you turn off the light before you left home?
3. Can we really reduce the carbon footprint of our homes?
4. Are you aware of the dangers of plastic bags on the environment?
5. Have you seen the `Young Voices for the Planet` films?
2. Listen and mark the rising intonation on the echo questions (↗). Then practise reading the exchanges.
1. A: ‘Plant for the Planet’ helped plant 12 billion trees worldwide.
B: Twelve billion trees worldwide? ⤻
2. A: Even when turned off, electronic devices use energy.
B: Yes, they can still use energy. ↷
3. A: Cutting down on energy use is the best way to help reduce global warming.
B: The best way to do what? ⤻
4. A: Global warming has catastrophic effects on humans.
B: Global warming has what on humans? ⤻
5. A: A single tree can absorb about one ton of carbon dioxide during its lifetime.
B: How long can a tree live? 

emissions
extinction
catastrophic
absorb
deforestation
carbon footprint
diversity
energy use  


1. I believe that the only way for us to reduce global warming is to cut down on energy use
2. Many species are threatened with extinction due to deforestation and loss of habitat.
3. Motor vehicles running on petrol are responsible for a large amount of carbon dioxide emissions
4. There are many ways for us to reduce our carbon footprint in order to save our environment.
5. More trees should be planted as they absorb carbon dioxide and give off oxygen.
6. The alarming rate of deforestation results in damage to the quality of the land.
7. Rainforests have the highest species diversity on the earth.
8. Global warming has proved truly catastrophic for the environment.
Complete the sentences with the words in the box.

Having + V3/ed
1. After the students had learnt about the benefits of recycling and reusing, they started collecting waste paper, bottles, and cans to recycle and reuse.
=> Having learnt about the benefits of recycling and reusing, the students started collecting waste paper, bottles and cans to recycle and reuse.
2. Since Mai had refused Nam`s offer of a lift in his car, she had to walk home.
=> Having refused Nam`s offer of a lift in his car, Mai had to walk home.
3. After Ha had read some documents about Green Earth, she decided to join the organisation.
=> Having read some documents about Green Earth, Ha decided to join the organisation.

Grammar
1. Rewrite the sentences using perfect participles.


4. Since the farmers used too much chemical fertiliser on their farm, they now have to drink polluted water.
=> Having used too much chemical fertiliser on their farm. the fanners now have to drink I polluted water.
5. After she replaced all the light bulbs in her house with LED lights, she saved a lot of money on her electricity bills.
=> Having replaced all the light bulbs in the house with LED lights, she saved a lot of I money on her electricity bills.
6. Since we have become too dependent on the use of electricity, we have to find alternative sources of energy before fossil fuels run out.
=> Having become too dependent on the use of electricity, we have to find alternative sources of energy before fossil fuel runs out.
Having + V3/ed
Grammar
1. Rewrite the sentences using perfect participles.
2. Combine the sentences using perfect gerunds.
1. Tonya had dumped a lot of rubbish on the beach. She was strongly criticized for that.
=> Tonya was strongly criticized for having dumped a lot of rubbish on the beach.
2. Sam had not worked hard enough in his previous job. He regretted it.
=> Sam regretted not having worked hard enough in his previous job.
3. Tony had rescued the kids from the fire. People admired him for that.
=> People admired Tony for having rescued the kids from the fire.
2. Combine the sentences using perfect gerunds.
4. I have seen him before. I remember that.
=> I remember having seen him before.
5. `You`ve lied to us,` the villagers said. The politician denied it.
=> The politician denied having lied to the villagers.
6. Thanh had forgotten to turn off the gas cooker before he left his house. He admitted that.
=> Thanh admitted having forgotten to turn off the gas cooker before leaving the house/before he left his house.
EXTRA EXERCISE
1….…… only three hours, I can hardly focus on my work.
Having slept b. was slept c. slept d. sleeping
2….……. up late is harmful for skin.
Staying b. to stay c. stayed d. have stayed
3….……. from so much trouble in the life makes her more and more mature than before.
Suffering b. was suffered c. has suffered d. suffered
4….……. this movie last week, I still wanted to see it again.
Having seen b. had seen c. was seen d. seeing
5.Mary is the cleverest person in the classroom. She is always the first person ……… the question.
To answer b. answering c. has answered d. answered
6.Her boss caught him ………. privately in the working time, so he was fired.
Speaking b. spoken c. to speak d. was speaking
7. Dan appears ………. some weight. Has he been ill?
Having lost b. having been lost c. to have lost d. to have been lost
8. Are you sure you told me? I don’t recall ………. about it.
Having told b. having been told c. to have told d. to have been told
9.Tommy made a bad mistake at work, but his boss didn’t fire him. He is happy about ………. a second chance.
Giving b. having been given c. to have been given d. to give
10.When I called them, they didn’t answer. They pretended ………. already.
To sleep b. sleeping c. having slept d. to have been sleeping
11….…….. the bottles, Mike poured the drinks for everyone.
To open b. to have opened c. being opened d. having opened
12.The painting was beautiful. I stood there ………. it for a long time.
To admiring b. admiring c. admire d. having admired