9. Seasonal variation in temperature and day length is due to ______.
A. Greenhouse effect
B. Tilt of earth’s axis
C. Spinning of the earth on its axis
D. Latitudinal variation in solar radiation striking the earth’s surface
A. Greenhouse effect
B. Tilt of earth’s axis
C. Spinning of the earth on its axis
D. Latitudinal variation in solar radiation striking the earth’s surface