How long do you suppose ______ we applied for the job ________ we had been trained . 

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

I don’t know ______ he will come tomorrow. ______ he comes , I’ll tell you.

You're the only person ______I've ever met ______could do it. 

—All the building materials have been washed away.—So I have heard. But there was no sign ____ a heavy rain was on the way last night.