4. Which is the first seismic wave to arrive at a seismograph station? A. Primary wave B. Secondary wave C. Rayleigh wave D. Love wave 18. А. 5 How many seismic stations are needed to locate the epicenter of an earthquake? A1 B. 2 C. 3 D.4 6. What should you usually do while an earthquake is taking place? A. Run immediately outside B. Get down and roll on the floor C. Duck, Cover and Hold 19 th A C 7. In this type of plate boundary, two tectonic plates are moving toward each other. A. Convergent B. Transform-Fault C. Divergent D. Convection​