The man was walking along the street        he stopped and looked as if                   whether he was going in the right direction. 

Yesterday I was just to go out _____ someone telephoned me.

Please remind me ______ he said he was going. I may be in time to see him off.

-- How long do you think it will be ____ the USA recovers from the losses of the financial crisis? -- Perhaps four or five years.

In his lecture, the professor referred to the belief ________ the elderly are wise, ________ is particularly dominant(支配的) in Chinese culture.