Here are the completed sentences using the correct forms of the given words:

1. Nowadays young people want to leave home as soon as they reach **adulthood**.
2. A good night’s sleep will improve your **concentration**.
3. Teens should learn to be **confident** when making a presentation.
4. Going away to college has made me much more **dependent**.
5. A lot of people eat too much when they’re **irresponsible** than I can handle.
6. I have a bad habit of taking on more **responsibility** than I can handle.