The correct answer is - wind speed goes above 74 miles per hour.
The tropical storms form over the tropical seas, where there's lot of warmth and bigger water bodies. When these tropical storms reach a point where the winds surpass speed of 74 miles per hour they enter into a faze of a hurricane.
The hurricanes are characterized with a low pressure center, which is also referred to as an eye. The wind speed is very high, 74 miles per hour or more. Intense rainfall is accompanying the winds. The hurricanes are very powerful, and they cause a lot of deaths and lot of material damage.
The answer is : 74 Mph Or Greater A tropical storm can turn into hurricane when wind speed goes above 74 miles per hour, which give it enough forces to destroy a hard concretes buildings that it passed by
The change to an ecosystem that is brought about by the biotic factors is the the landslide caused by the cattle overgrazing. The answer is letter C. The word biotic means the factor should be living thing (s). Among the choices, only the cattle is living organism.