1. Someone had started a forest fire. Tom admitted that he had done it. 2. Students in Grade 11B had planted many trees in the schoolyard. They were praised for that. 3. After we made all necessary preparations, we put out plan into action. 4. After I had watched the documentary about wildlife, I made a donation to an environment society.

1. Tom admitted (to) having started a fire in the forest.

2. Students in Grade 11B were praised for having planted many trees in the schoolyard.

3. Having made all necessary preparations, we put out plan into action.

4.  Having watched the documentary about wildlife, I made a donation to an environmental society.

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1.  Tom admitted having started a fire in the forest. ( admit V-ing : thừa nhận)

2. Students in Grade 11B were praised for having planted many trees in the schoolyard. ( praise : khen ngợi)

3. Having made all necessary preparations, we put our plan into action. 

4. Having watched the documentary about wildlife, I made a donation to an environmental society.