听力原文：The Antarctic is probably the most difficult place on earth for human beings to s

听力原文： The Antarctic is probably the most difficult place on earth for human beings to survive. For six months of the year there is total darkness, and temperatures may fall as law as -88~C. Even in the summer months the temperature is often below zero.

The first successful expedition to the South Pole was led by Ronald Amundsen. His team used dogs and sledges to cress the frozen continent, and reached the pole in December 1911. in 1928, Richard Byrd decided to lead an expedition to the Antarctic to explore the unknown area from the air for the first time. It was the largest and best equipped expedition that had ever set out for the Antarctic. Byrd and his team established a base which they called Little America on the coast of the Rosa Sea. In November 1929, during the Antarctic spring, Byrd and three colleagues flew from the Little America base to the South Pole and back in 19 hours.

Byrd's major achievement was to introduce the use of aircraft ,radio and other devices in polar exploration. He did not agree with Ronald Amundsen that the airplanes would one day replace dogs and sledges; he believed that modern techniques were only an addition to the traditional methods of exploration. All of his expeditions, therefore, carded dogs and sledges, and people to look after them. This proved very efficient, and Byrd was able to achieve results of great scientific value.

What is the lowest temperature in the Antarctic？

A．-50℃.

B．-68℃.

C．-70℃.

D．-88℃.