7. Having  raplaced all the light bulbs in her house with LED lights, she same a lot of money on her electricity bills

8. Sam regretted for not worked hard enough in his previous job

9. The police suspected Mike for cutting down the oldest tree in the park

10. Having use too much chemical fertiliser on their farm, they now have to drink polluted water.

11. Denis was rewarded for had taken an active part in the Green Summer activities

12. Having learnt about the benefits of recycling and reusing ,the students started collecting waste paper, bottles, and cans to recycle and reuse

Đáp án:7.After she raped all the lights in the house with LED lights, she made a lot of money on the electricity bill.

          -> Having a lot of money in the electricity bill because she assembled all the lights in the house with LED lights.

            8. Sam had not worked hard enough in his previous job.He regretted it.

         --> Sam regretted when he didn't work hard at his previous job

            9. Someone had cut down the oldest tree in the park. The police suspected Mike of doing it.

        -> The police suspected Mike cut down an old tree in the park

            10. Since the farmers used too much chemical fertiliser on their farm, they now have to drink polluted water

        -> Having used fertilizers on their farms, they had to drink contaminated water

            11. Denis had taken an active part in the Green Summer activities.He was rewarded for that.

         --> Denis was a very active person involved in Green Summer activities because of that, he was rewarded

            12. 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 students to collect paper, bottles and cans for recycling because they already know the benefits of recycling and recycling.