answer:Maslow's hierarchy of needs is a motivational theory that describes the five levels of human needs. It starts with physiological needs for survival, followed by safety needs, belongingness and love needs, esteem needs, and self-actualization needs. The theory suggests that people are motivated to fulfill the lower needs before they can move on to the higher needs. Once each need is fulfilled, individuals can move up the hierarchy to reach their full potential and ultimately, self-actualization.

answer:You can use the following code to reverse a string in Python: ```python string = "Hello, world!" reverse_string = string[::-1] print(reverse_string) ``` Output: `!dlrow ,olleH`

answer:Area of a triangle = (base * height) / 2.

answer:Subject: The dog. Predicate: Barked at the mailman.