Well to find this out you need to make an equation
s+7=j
So for example if Johnny's sister is 15 then Johnny would be 22 because
s(sister's age) +7(number of years difference between their ages)=22(Johnny's age)
The correct answer is - temperature.
We see the stars on the night sky in multiple colors, and the variation in the colors of the stars comes from the differences in temperature. The cooler a star is, the more reddish it appears, the hotter the star is the more blueish or whitish they appear. From cool to hot, the stars can appear in the variations of red, orange, yellow, green, blue/white colors, and it is an easy indicator of the temperature of them.
It called for more local control and free-market practices.
B. Crystal size is a function of cooling time. The longer a melt cools the larger the crystals.
