Hello chegg expert please I need the correct and complete answers of those questions they are very important for me and in the same time it's urgent very very urgent please please help me I need your help .

Question 2-1. Recursion plays an important role in algorithm design. You are required to give your understanding about recursion, such as the definition and where it can be used.

Question 2-2. In our real life, many different methods can be used to solve a given problem (e.g. sorting). Do you know how to make a better choice? Please write down your idea and reasons.

Question 2-3. Compare the differences between selection sort and quick sort, and give your understanding about the divide-and-conquer algorithm.