Để hoàn thành đoạn văn, các từ phù hợp có thể được điền như sau:

1. **vital**
2. **support**
3. **free**
4. **together**
5. **difficult**
6. **stressed**

Vậy đoạn văn hoàn chỉnh sẽ như sau:

The Importance of Friendship
Friendship is a **vital** part of a teenager's life. Friends provide **support** and companionship during a time of many changes. Many teenagers enjoy spending time with friends at school and in their **free** time. They might hang out at the park, play video games, or go to the movies **together**. Good friends help each other through **difficult** situations. When a teenager is feeling down or **stressed**, a supportive friend can make a big.