The answer is a. Number 2 is colombia
Seismograph's drum feel the seismic waves. There is a weight that moves the pen so that when the seismic waves are felt, the pen jiggles and records it on paper.
Biotic factors are organisms that interact with non-living & living parts of an ecosystem.
Egs. badgers, worms, fungi, bacteria, insects.
In 1815, Mount Tambora erupted on Sumbawa, an island of modern-day Indonesia. Historians regard it as the volcano eruption with the deadliest known direct impact: roughly 100,000 people died in the immediate aftermath.
