3. Why is there an abrupt change in the speed of seismic waves as they travel inside the Earth? It is because seismic waves are
A. colliding
B. overtaking the compressional waves
C. passing through a material with the same density
D. going into a material with different properties and densities

4.Which of the following waves travel the fastest and are detected first in the
seismic station?
A Love
B. primary
C. secondary
D. surface

5.Which kind of waves does NOT travel through a liquid?
A. Love
B. primary
0. secondary
D. surface

6. What type of seismic waves that are responsible for a destructive earthquake?
A. Love
B. primary
C. secondary
D. surface​