They had hunted and killed many wild animals. Later they regretted what they had done.

He had dumped lots of rubbish onto the beach. He denied it.

After she replaced all the light bulbs in her house with LED lights, she saved a lot of money on her electricity bills.

Thanh had forgotten to turn off the gas cooker before he left his house. He admitted that.

I have seen him before. I remember that.

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

Since we have become too dependent on the use of electricity, we have to find alternative sources of energy before fossil fuels run out.

Since Mai had refused Nam's offer of a lift in his car, she had to walk home.

Tonya had dumped a lot of rubbish on the beach. She was strongly criticized for that.

Tony had rescued the kids from the fire. People admired him for that.

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

The factory had dumped tons of toxic waste into the river. It was heavily fined for that.