—Putting on a happy face not only helps us make friends but also makes us feel better.— __________.
Only when the villagers were faced with water shortage___ how serious the problem of water pollution was.
Only by practicing every day ___________ English well.
Only when 1 was fourteen__________the importance of study.
Only after the plane had taken off _________ that he missed his parents so much.
Only when I left my parents for Italy __ how much I loved them.