Seismometers are tools which measure motion in the ground including seismic waves generated by earthquakes, volcanoes, and other activities which might create seismic waves. Seismometers measure any movement of seismic activity in the earth and today this is done by electronic means whereby the machine measures any changes in seismic activity in the surrounding areas of the seismometer. The first seismometer is believed to have been invented by Zhang Heng of China's Han Dynasty in 132 AD.
It is continent cause there is no term for many continents because continent is the biggest landmass.
I know 6 is multiplying by 3 but idk the other ones
Answer:
Keeping lakes and rivers free of pollution.
Explanation:
