How is it that the experimental method allows researchers to draw cause-and-effect conclusions?

Which sentence best represents the thesis of this article? a they challenge us to consider whether we can trust what we are seeing. b optical illusions may seem mysterious, but they are not unexplainable. c through science, we can learn how optical illusions work. d let’s take a look at three common optical illusions and explore the science behind each one.

Below is a description of a resource that you're considering using for a research paper. as you read the description, keep in mind what you've learned about historical thinking skills and use those skills in evaluating whether or not to use the source.

An externality can be created by a. people working at a production job and enjoying their work b. a production activity but not a consumption activity c. a consumption activity but not a production activity d. a production activity or a consumption activity externalities a. are always positive, and an example is flu vaccinations b. are always negative, and an example is the pollution created by trucks c. can be negative or positive. logging has a negative externality, and education has a positive externality d. can be negative or positive. a negative externality is having to go to school when you would rather go to the beach, and a positive externality is spending time with your friends