根据汉语用所学短语的正确形式填空。
1. Galileo's observations show that Copernicus, another great astronomer, was right and that the earth
moves around the sun, not ______ (相反).
2. Three years ______ (过去), but he was still alone.
3. The old should be ______ (尊敬).
4. Our teachers ______ (不遗余力) to help us in our daily life.
5. He ______ (充当) chairman in my absence last year.
