The entire route would ordinarily take the postal service 25 days, but that was far too long. Under the rough trail conditions, the medicine would only last six days. The dogs would have to complete the journey in less than a quarter of the normal time.

　　Many of the dog team drivers who took part in the run suffered frostbite (冻伤). By January 31, 1925, Leonhard Seppala's Siberian Huskies had travelled 170 miles from Nome to meet the oncoming medicine delivery. With just two days before the deadline, Seppala made the decision to cross the unstable Norton Sound. Then a snowstorm closed in, and Seppala found it impossible to see anything. To survive, Seppala relied on his lead dog Togo to lead the way through the Norton Sound. That brought the medicine 91 miles closer to Nome. He handed the medicine off to Charlie Olson. Another driver named Gunnar Kaasen then stepped in, with a team of dogs led by a Siberian Husky called Balto. They delivered the medicine to Nome with half a day to spare, saving about 10,000 lives. The story made Siberian Huskies famous. The statue of Balto is a popular tourist attraction in New York's Central Park.

　　语篇解读：本文是记叙文，以1925年美国阿拉斯加Nome镇白喉病事件为背景，描述了哈士奇狗拉雪橇队为了及时把救命药运送到Nome镇所作出的贡献。

　　24．Which of the following can replace the underlined word "fatal" in Paragraph 2?

　　A．Deadly.　　　　　　　　 B．Abnormal.

　　C．Curable. D．Stable.

　　解析：选A　词义猜测题。根据语境可知，此处表示如果白喉病得不到医治的话，将会产生致命的影响。画线词意为"致命的"，同deadly含义相近。

　　25．Why were dogsled teams used to transport the medicine?

　　A．The postal service was out of use.

　　B．People there had a preference for dogsleds.

　　C．Diphtheria would be passed on to human senders.

　　D．Dogsleds could progress in that extreme weather.

　　解析：选D　推理判断题。根据第三段中的"Nome was cut off by the worst winter in 20 years and there was no local stock ..."及"On January 24, 1925, Nome's Board of Health voted to use a dogsled (狗拉雪橇) relay to transport the medicine from Nenana to Nome"可知，Nome镇被极端天气所困，与外界隔绝，当地卫生局投票决定利用狗拉雪橇队来运送治疗白喉病的药。故选D。

26．Why did the teams have to complete the journey within six days?