1. • Why can we see sunrise and sunset?
   • When the earth goes round the sun, what season do we have on the part that is towards the sun?
   • When both halves of the earth are the same distance from the sun, what season do we have?

We all live on the earth. The earth turns round once a day. As it turns, some people see sunrise and day comes to their houses; at the same some people see sunsets and night comes to their houses.
The earth moves in another way, too. If it travels round the sun in an orbit towards the sun, it is summer on that part of the earth. Half a year later, the earth goes round to the other side of its orbit. That part of the earth is now farther away from the sun and has it winter and the other part has its summer. Between summer and winter, both halves of the earth are the same distance from the sun. Then they have spring and autumn. As the earth goes round in its orbit, we have our four seasons go on and on.