8. Stella thinks that if people are exposed to ultraviolet light, then they are more likely to get skin cancer. Stella designs an experiment wherein sample A consisted of people were exposed to ultraviolet light and sample B was not.

firearm identification is the process of analyzing the bullets and cartridge cases left at a crime scene to determine if they came from a particular firearm. marks on the bullets and cartridges may be common to every firearm of that type. these are called class characteristics.