Understanding the concept of recursion is an important skill in programming.

You should protect your own health.

A verb plays the role of expressing actions or states in a sentence.

Your application is not covered.

He is using that coat from winter to spring.

You need to use your head to solve this problem.

He used himself as a reflexive pronoun.

Understanding the algorithm of the regression tree is difficult.

Using tail recursion can sometimes improve the performance of a program.

This program has recursivity.