Answer:
it's b because it's literally b
The Chinese people invented the Seismometer during the Han dynasty to help predict natural disasters. The Seismometer measured the motion of the ground, and things included of seismic waves such as, earthquakes, volcanoes, and other things that involve explosions that are generated by seismic waves.
Answer:
problems starting to form
B. -1
y2-y1/x2-x1
(-1,3). (3,-1)
-1-3/3+1
-4/4
-1
Singapore is the correct answer.