شرکت در آزمون آنلاین انگلیسی 3 - انگلیسی 3 | آزمون شماره 10694

If you go through what happened to these companies, there will be clear ......... to be drawn from their failure.

..................................... energy sources such as hydropower , wind or water operate differently to generate electricity.

............................ is common in all countries all over the world among those who have higher education.

Solid wastes are either burnt or buried in .............................  tips and fluid wastes are dumped in the sea .