Answer:
Most people want that is good at preventing unintended pregnancy. Fortunately, all methods of birth control are better at preventing pregnancy than using no method, but some methods are better than others. How well a method works, though, depends on many factors. It’s important to understand how these factors affect each method’s ability to prevent unintended pregnancy, and how researchers describe how well the methods work.
Explanation:
Researchers measure how well a birth control method works in two ways: perfect-use and typical-use.