31. People’s carelessness can cause forest fires.
Forest fires can be caused by people’s carelessness.
32. I don’t have a computer, so I can’t send an e-mail to you.
If I have a computer, I can send an e-mail to you.
33. We should do something to save our planet which is being destroyed seriously.
It is good to save our planet which is being destroyed seriously.
34. She is writing an article about environmental problems.
An article was writted about environmental problems (by her)
Bn tham khảo nhé! Mik ko chắc là đúng đâu ạ!
Học tốt!~