In nineteenth-century America, people shared beds, both at homes with relatives and in hotels with strangers, without inquiring about their bed partner’s health. They exchanged combs, hairbrushes, and even toothbrushes, and they fed babies from their mouths and spoons, with no sense of danger. They coughed, sneezed, and spat without concern for their own health or the health of those around them. They cooked and stored their meals with little worry about food-borne illness. They drank unfiltered water from wells and streams, often using a common dipper or drinking cup. Last but not least, they used chamber pots and outhouses with little regard for where the contents ended up in relation to the community water supply. The sentence that best expresses the implied main idea is: