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。

　　4．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。

　　5．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。

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

　　A．The trail would be cut off soon.

　　B．There was not enough food for dogs.

　　C．The medicine couldn't last any longer.

　　D．The patients could only wait for that long.

　　解析：选C　细节理解题。根据第四段中的"Under the rough trail conditions, the medicine would only last six days"可知，在艰难的运送过程中，这种救命药只能持续6天。因此，雪橇队必须在6天之内完成救命药的运送。故选C。

　　7．What's the best title for the passage?

A．A Race Against Death