[填空题]Seismologists can measure the size of sea waves.

[填空题]Seismologists can measure the size of sea waves.

[单项选择]An accidental discovery has brought seismologists(地震学家) one step closer to being able to predict earthquakes. As part of an unrelated effort to measure underground changes caused by shifts in barometric pressure (大气压力), a team of researchers found that increases in subterranean pressure (地下压力) preceded earthquakes along California’s San Andreas Fault(断层) by as much as 10 hours. If follow-up tests advance the findings, seismologists may eventually be able to provide a few hours’ notice for people to find safe places prior to quakes.
Researchers used a high-tech equivalent of a stereo speaker lowered into a bore hole near Parkfield, Calif., a half-mile deep and five yards from a measuring device. For two months beginning in late 2005, researchers transmitted pulse signals three times per second, from the speaker to the measuring device, calculating travel time between the two stations. Surprised scientists learned the seismic waves slowed dramatically on only two occasions: two ho
A. Researchers will test in more seismically active places.
B. Researchers will drill more deep holes along the fault lines.
C. Researchers need to eliminate some factors which might affect seismic readings.
D. Researchers need to do more in their detecting systems.