Масса мальчика 50 кг. Какое давление он оказывает на лёд, если площадь его ступни 125 см²

какая пишется в предложениях   a  или The 

1.Is it easy to live on ...... Moon?

2. ...... Moon goes round......Earth.

3. ...... last summer we went to ...... South. ....... weather was good.We could see ........ lot of ........stars in ........ sky at ...... night.

4. ....... David thinks he is ........  best pupil in ....... world.

5. ........ Earth is ....... planet .

6. ......... Earth is....... planet we love on.

7. ......... Indian Ocean separates....... Africa from...... Australia.

8. What islands in........Atlantic Ocean can you name?

9.Is .......Pacific Ocean........ biggest of all........ oceans?