【单选题】

In the people’s Republic ofChina the odd prequake behavior of horses and other animals (1) successfully to warn people that earthquakes (2) . Recently, a group ofAmerican geologists and geographers visitedChina and listened with great interest (3) the scientists there (4) explained how they have been able to predict many earthquakes in the past three years. TheAmerican scientists compared the (5) of the uniqueChinese program (6) the impact ofChinese acupuncture (7) Western medicine.

TheChinese scientists use (8) but they also monitor strange (9) such as various ground noises, the fluctuation of well-water levels, and the strange behavior of animals. The results are quite interesting,Chinese seismologists, for example, (10) predicted two magnitude 6.9 quakes near theChina-Burma (11) on May 9,1976. The seismologists say that their predictions have been (12) precise that they were able to evacuate many of their people (13) an earthquake occurred, (14) saving thousands of lives. (15) , theChinese experts also admit that there have been some false alarms.
American scientists have (16) stories of unusual prequake animal behavior before, but they (17) them too seriously until their recent visit toChinA、"Maybe there’s (18) in it", said JackEverndon, aCalifornia scientist. 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 (19) enough to give it a serious look," he commenteD、"Two years ago we (20) that.\
A、signalsB、things C、animals D、matters