آزمون آنلاین زبان انگلیسی 1 - درس 4 | آزمون شماره 9631

Iranian people believed that it was their ......... to help those who had lost their homes in the earthquake.

His recent ............................. is because of his advancing age and that's normal, isn't it?

Another interesting source of energy is the heat that ............................ be recovered from radioactive waste material.

.......................... is the mother of invention. It means that we invent things when we are in need of them.

Even on holidays , she is ............................ the Internet for more information about her business .