Answer:
They are weather systems that happen to spin in a counterclockwise direction in the Northern Hemisphere from low pressure points. They form between two big cold fronts when their temperatures are very different compared to each other. These air masses will blow past each other in opposite directions when it is formed.
"The Silurian is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at 443.8 million years ago, to the beginning of the Devonian Period, 419.2 Mya.<span> <span>Wikipedia."
https://www.google.com/search?q=He+Silurian+period+occurred&rlz=1C1RUCY_enUS760US760&oq=He+Silurian+...
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Answer:
Prediction.
Explanation:
A prediction is often written as an if/then statement.
This ultimately implies that, a prediction is based on hypothesis that hasn't proven yet or isn't backed up by any evidence. Thus, it is typically an if statement that also leads to an outcome (then).
