单项选择题

In the People’s Republic of China the odd prequake behavior of horses and other animals has been used successfully to warn people that earthquakes are about to occur. Recently, a group of American geologists and geophysicists visited China and listened with great interest to scientists there who explained how they have been able to predict many earthquakes in the past three years. The American scientists compared the influence of the unique Chinese program with the influence of Chinese acupuncture on Western medicine.
The Chinese scientists use modern electronic equipment--but they also monitor strange signals such as various ground noises, the fluctuation of well water levels, and the strange behavior of animals. The results are quite interesting. Chinese earthquake experts, for example, successfully predicted two magnitude 6.9 quakes near the China-Burma border on May 29, 1976. The earthquake experts say that their predictions have been so precise that they were able to remove many of their people before an earthquake occurred, thus saving thousands of lives. On the other hand, the Chinese experts also admit that there have been some false alarms.
In the most intensive effort on earth to predict earthquakes, an army of Chinese professional and amateur quake watchers is organized to obtain daily information about ground movements wherever a major tremor is anticipated. The volunteer observation teams use electronic instruments and listen for earthquake warning signals that have been described in old records. According to these historical records, farmers had known that something was very wrong in the earth beneath them whenever horses reared and raced, dogs howled, and fish leaped. Also animals such as snakes and rats that people saw rarely, suddenly came out of their hiding places by the dozen. Some records said that sounds like thunder could be heard coming from the ground in the days and hours just before an earthquake. In some cases, swimmers could hear underwater sounds that people on land did not hear. Also, clear well water usually became muddy and the water levels of the wells changed.
The Chinese methods of prediction are probably based on intuition and experience with many major earthquakes. Three thousand years of historical records show that China suffered its greatest natural disaster when earthquake in 1556 killed more than 820,000 people. At present, China averages six quakes of at least 6.0 on the Richter scale each year, whereas the United States averages two or three per year, mainly in the Aleutian Islands of Alaska.
American scientists have heard stories of unusual prequake animal behavior before, but they never took them too seriously until their recent visit to China. "Maybe there’s something to it," said Jack Everndon, a California earthquake expert, "We need some kind of short term warning. We need something."
He didn’t mention the kind of research he may be considering. "Some of us are thinking it’s worthwhile enough to give a serious look," he commented. "Two years ago, we wouldn’t have said that.\
What is the main idea of this passage