Suppose every person on earth ate only one kind of food. And one year later, that food couldn't be found . If that happened, man would soon die.

     （1）, man doesn't face that problem. But another animal may. The animal is the giant (巨大的) panda, one of the world's most beloved  （2）.

    Dr. Thomas Soderstrom, a scientist, has found for the first time that the bamboo (竹子) the giant pandas eat is dying. as a result, many of the pandas are also dying of being hungry. Scientists estimate (估计) that so far more than 140 giant pandas  （3）. This number may be almost one quarter of the world's giant panda population. Between 400 and 1,000 giant pandas are believed to live in mountains. Giant pandas were once more common all over many parts of Asia (亚洲). Now they are only in small parts of China.

     Can the wild pandas be saved ? The scientists want to find  （4） more about the animals' food. They want to see whether the pandas are able to change their food while the bamboo is dying.

     Chinese scientists are trying  （5）more pandas in zoos.