1. formaldehyde
2. paradichlorobenzene
3. tobacco smoke
4. toronto smog
5. pesticides
<span><span>A plant that, when self-fertilized, only produces offspring with the same traits.</span></span>
A chase of cheetahs and lions and how they hunt the same prey and have to compete to get it first.
Sarcoma- 'Sarcoma' means malignant tumour.