IEmplois Fome Les prons relatifs presentent des formes simples et des formes composees Les formes simples: gui, que quoi sont invariables en genre et en nombre; ce ne sont que des formes differentes du meme pron gui (on range aussi dont ou parmi les formes simples)
Pre-reading Questions 1. Name several pollutants 2. Who causes pollution? 3. Why is pollution one of the most serious problems that man faces these days? 4. Why is the pollution problem complicated? 7. 5. How can pollution be gradually reduced? 6. When did man begin to pollute his