普朗克是诺贝尔物理学奖的得主，于1913年曾亲赴瑞士，礼聘尚是一介书生的爱因斯坦

Having said good-bye to his parents, Alvin, with his wife and one-year-old son, set off back home. Still ____36__, Alvin and Clare talked and laughed happily. And even little Alax  ___37__  from time to time. The family were ___38__ their trip.
But about three hours later things began to ___39__. It was starting to snow. Alvin ___40__ up the car, hoping to arrive home before dark. But it was too dangerous to drive fast now. Because it was snowing more and more heavily. So Alvin had to __41___down. The snow on the    __42___ was getting deeper and deeper until it was hard to __43___on it. Their car slipped of the way and got ___44__in the deep snow and the engine refused to start again. “The snow doesn’t seem to __45___. Shall we stay in the car waiting to be frozen to death or walk ahead through the snow?” Alvin asked. Clare said she __46___to walk. So they got out of the car with their son and began walking. But __47__was to come. Soon they lost their way and had to walk ___48__on and on.
Night came. They were not afraid of the dark. But they __49___that poor Alax would die of cold. However, their faith to keep Alax __50___ filled them with courage, warmth and strength. They ___51__ and rested in turn and then continued their walk. They had ___52__falls but each time true love encouraged them to rise to their feet again.
One, two, three, … seven days passed. On the eighth day, help at last came from Alvin’s  __53___, the police and local people. But the young __54___had to have their feet cut off because of the bad frostbites（冻伤）___55__, there was nothing serious wrong with little Alax!