An abstract usually contains one or two key sentences from each section of a paper. Read the following extract from somebody's draft abstract. Match a section to the extract.

With die aim of evaluating this possibility two microorganisms, Acidithiobacillus ferrooxidans, an acidophile, and Deinococcus radiodurans, a radiation-resistant microorganism, were exposed to simulated Mars conditions; that is, 95% CO,, 2.7% N,, 1.6% Ar and 0.6% H,O with a pressure of 7 mbars. Temperature was set at 150 К and ultraviolet radiation was in the wavelength range of 200-400 nmat. Exposure was for different times under the protection of 2 and 5 mm layers of oxidised iron minerals. Survival was evaluated by growing die organisms on fresh media.