It was not until 1911, _______ the first vitamin was identified, _______ people realized the importance of it.
I’m glad I went over all my notes; otherwise _____ .
--- “Have you ever been to Beijing?” --- “No, but I wish I _____”
A few minutes earlier and we _____ the rain.
I _____ you some money, but I hadn’t any on me then.
He treated me as though/as if _____ his own son.