ANSWER: the ring of fire is a major area in the basin of the Pacific ocean where many earthquakes and volcanic eruptions occur.
Answer:
The core is made of two layers: the outer core, which borders the mantle, and the inner core. The boundary separating these regions is called the Bullen discontinuity. The outer core, about 2,200 kilometers (1,367 miles) thick, is mostly composed of liquid iron and nickel.
Answer:
D people today live longer,healthier lives than 200 years ago
