7.5 too, its kinda of ratio, 1cm : 1Km to 7.5cm : x
x will be equal 7.5 km
The answers would be wind speed, air pressure, and wind direction.
Wind speed and air pressure are necessary to show how fast the windmill is going, and the wind direction is necessary to show which direction the windmill is going.
Option C would be correct. The organ system can plays many parts at one time. Also, it is the only system listed.
Hope this helps!
Alexander Fleming is the answer ;D
