Explanation:

- Communication is vital for human development. It allows people to express ideas and connect with others.

- Learning communication requires personal effort. Practice improves skills in reading, writing, and speaking.

- Professional success often requires good communication skills, enabling effective information exchange.

- Barriers in communication disrupt this process, making it necessary to address them.

- To ensure smooth transmission of messages, it's important to deal with or address these barriers.

Let's review the options for blank No. 5:

1. Strengthen: Implies making something stronger, which doesn't fit the context of dealing with obstacles.

2. Overcome: Means to successfully deal with or defeat issues, which fits the need to remove communication barriers.

3. Succeed: Implies achieving a goal, not directly about addressing barriers.

4. Create: Implies causing something to exist, not relevant to removing obstacles.