1)I'm very busy ,so I can't help you now
->If I weren't .......
2)they have rebuilt many roads in this city
-> many roads have.......
3) I didn't understand the lesson because I was absent from class yesterday
_> if I hadn't
4) human beings are therateing the nature
-> the nature is.......
5) mary learns very hard because she wants to get good marks
-> if mary......
Giải nhanh hộ m