有关地震波的说法,正确的是( )
A:地震波就是横波
B:横波的传播速度较慢,可以穿过固态、液态、气态三态物质
C:纵波的传播速度较快,可以穿过固态、液态、气态三态物质
D:纵波传播的速度随经过的物质不同而发生变化,而横波不变
The little pupil took his grandma ____ the arm and walked her across the street.