These subs are useful in studying the ocean floor, where it is so deep that divers would be crushed by the water pressure. For example, research submersibles are used to study shipwrecks like the RMS Titanic.
What are the factors? If you meant to attach something it's not there.
Answer:
B. Rock and soil that is removed to mine ore.
Explanation:
Overburden is a material or substances that is present above the metal ore. This metal ore is present inside the rock and soil so for its extraction the rock and soil must be removed that is present above it. Metal ore such as gold, silver,coal, iron and platinum are present inside the earth crust. These metals are not present in pure form some soil particles or other substances are present with it which is removed with the help of various instruments and machines.
C IT DEPENDS ON A VARIETY OF FACTORS
They do not occur only during spring they occur when the sun, moon, and earth are all alined.
