根据下列各个句子的要求，完成、改写或翻译句子。
71. As soon as the volunteers reached Yushu, they set out to work. (改写)
_______ _______ _______ the volunteers ________ Yushu than they set out to work.
72. I didn’t realize that he was a famous football player until he took off his dark glasses. （改写）
______ ______ ______ ______ he took off his dark glasses that I realized he was a famous football player.             
73. Shanghai World Expo is a window. The world can come to know China through it.
Shanghai World Expo is ______ _______ ________ _______ the world can come to know China.
74. Travel can give people relaxation and pleasure. And it can increase people’s knowledge of any kind, too. (用not only…but also 改写句子)
75.毋庸置疑，事故是由于司机的粗心引起。(翻译)
There __________________________________________________________.
76. After I rested on a stone for half an hour, I felt refreshed. (改写成一个简单句)