What were the three goals of the lewis and clark expedition

How can changes in technology or consumer demand make it difficult for people to get jobs? by changing the number or kind of jobs available by making it possible for some people to work fewer hours by making it difficult for people to buy what they want by creating a demand for things that are not available

Whether or not a given study has the possibility of causing harm to participants:

Are people more motivated to change from positive or negative experiences, like slavery, womens rights, and any other historical movements/moments? i need more factual information than opinions.