1. We breath oxygen and exhale carbon dioxide.
2. It is dangerous to live in the area full of gases and toxic fumes.
3. Unfortunately, many factory waste leak to rivers and ponds, which cause ecological problems.
4. Her handwriting is too small and slim - I can't make anything out of her work.
5. A cold snap and sleet are predicted by the weathermen tomorrow - it is time to find my warm jacket.
6. Our airplane is soon going to land, we need to fasten our seat belts.
7. I don't believe you - you've probably made this story up!
8. Don't eat that apple, it is poisoned!
9. We're lost - let's follow that fast stream.
10. This fog is too thick - I can't see anything!