--Would you permit me _______ here?---Sorry.We don’t permit ________ in the library.A smoking;smoking B to smoke; to smoke C smoking; to smoke D to smoke;smoking
One solution to this problem now is sustainable development.
Wind power units are placed ______ there is a lot of wind.
Recently, there a boom in population movements.
______developing countries need to do is to stop poverty.
That's the best way you thought of _______ into dangerous areas.