Put the questions to the sentences below.
1. The sun is the centre of the world.
2. English is a world language.
3. When Ann came to the new school she saw many trees around it.
4. The earth is a source of our wealth.
5. Mineral water in bottles is always drinkable.
6. Even good pupils couldn't do the exercises in physics.
7. Activity in learning helps students to get better results.
8. A lot of harm to the forest was done by fire last year.
9. Nobody knows who set fire to the new building.
10. It is always important to keep your body clean.
11. He raised his right hand to protect his face.
12. The environment is natural conditions such as air, water, land and others.
13. The wood was polluted with smoke from the chemical mill.