china
It was invented in china in ancient tokyo by your mother
frog
they used a seismograph
If for ancient China, (i am assuming because you said did) it is seismograph
when zhang heng who seismograph invented it now people now when a earthquakes
Chang Heng, a Chinese scientist, invented the first seismoscope around 132 AD called the dragon jar
It's important because it told the ancient Chinese which direction the earthquakes were from up to 310 miles away.
the ancient Chinese civilization invented it
The first "modern" seismograph was invented by John Milne in 1880. However, Zhang Heng, a Chinese astronomer is also believed to have invented the seismograph; probably the primitive ones.
The ancient chinese
The ancient Chinese had rockets.
the Chinese