<span>A SI base unit is the single and direct measurement unit for a physical entity. E.g. For mass it is kg, for time it is sec, A derived unit is determined by a physical equation with the base units, like for velocity equals distance divided by time, in SI units: unit of v (velocity)= m (meter) divided by sec (seconds).
Hope this helps!</span>
It is A I took it befor hope this helps:)
We have seasons on earth because of the way the earth is tilt on its axis. at a certain time in the year, the sun's rays reach certain parts of the globe more than others.
some places have 4 seasons because they are in the northern hemisphere, which is in the sweet spot of the sun's rays that give us each season. other places only have 1 or 2 because they are not in the northern hemisphere.
