Passage Two

As protector of her family’s health, the poineer woman confronted situations she never imagined before crossing the Mississippi. Few women came West prepared to deal with desert sunburn, rattlesnake bites, or arrow wounds. Even when doctors were available, they were of- ten no more knowledgeable than their patients. And most patent (专利) medicines were no more reliable than the itinerant (巡游) merchants who sold them. In certain cases, a woman could draw upon the folk wisdom and remedies she had learned back home; Western mosquitoes, for example, proved to be as repelled by a paste of vinegar and salt as were their Eastern cousins. More often, however, a woman was guided only by her own ingenuity in concocting (调制的) tonics (补药), powders, poisons, and polishes from whatever she had at land: salt made a passable toothpaste, gunpowder was applied to wants, and turpentine to open cuts, goose grease, skunk oil, and the ever present lard were basic liniments; medicinal teas and tonics were brewed from sunflower seeds and roots.

Which of the following can be inferred from the passage about patent medicines（）