Respuesta :

a few examples are:

1)The position of the earth in its orbit around the sun. 
2)the position of the earth as it rotates around its axis 
3)the angle of the axis tilt. 
Maryfenelli

1. The position of the earth (The Earth is tilted about 23 degrees so as it goes around the sun light strikes the planet's northern hemisphere more directly in summer than in winter.)

2. Gravity

3. Friction

4. Radiation

Just some thoughts