Most natural changes happen slowly, although events such as fire, tornadoes, flooding, or insect infestations can change an ecosystem dramatically in a short time.
(Most natural changes; happen slowly; ) (events such as fire, tornadoes, flooding, or insect infestations; can change dramatically; T:in a short time)
Most natural changes events such as fire, tornadoes, flooding, or insect infestations
happen slowly can change dramatically
T:in a short time