TOEFL Reading: ETS-TOEFL阅读机经 - A3O1C2156U7LP1OML$

Earthquake prediction is not highly developed at the present, but research continues in this important field of study. A. Short-term forecasting has been used more widely than long-term forecasting in the prediction of earthquakes. B. Long-term forecasting of earthquakes uses data on past seismic activity to determine the likelihood that an earthquake will occur in a certain area within a certain time period. C. Short-term forecasting research has studied earthquake precursors such as volume increases in rocks and unusual movements in underground water that occur shortly before an earthquake takes place. D. The dilatancy model has been used to successfully forecast some recent earthquakes. E. Attempts to improve forecasting by using five stages of earthquake predictors have been unsuccessful because each earthquake has unique precursor patterns and durations. F. The magnitude 6.9 North American earthquake in 1989 was not successfully predicted because the many foreshocks before the event were too small to measure.