Are these sentences using commas correctly or incorrectly? 1) If students cannot concentrate for sustained periods of time, they will not master a skill necessary for problem-solving, and, as a result, they will be less likely to become independent, creative citizens.

2) If students cannot concentrate for sustained periods of time they will not master a skill necessary for problem-solving, and, as a result, they will be less likely to become independent, creative citizens.

3) Students who cannot concentrate for sustained periods of time will not master a skill necessary for problem-solving; and, as a result, they will be less likely to become independent, creative citizens.

4) Students who cannot concentrate for sustained periods of time will not master a skill necessary for problem-solving, hence, they will be less likely to become independent, creative citizens.

5) The internet contains many enticing distractions, such as pop-up videos mindless games, and phony news articles that lead us on a path to nowhere.

6) The internet contains many enticing distractions. Such as pop-up videos, mindless games, and phony news articles that lead us on a path to nowhere.

7) The internet contains many enticing distractions, such as pop-up videos, mindless games, and phony news articles that lead us on a path to nowhere.

8) People, who are addicted to the web, struggle to function in situations that require quiet concentration, and grow frustrated easily when faced with exercises that require patience.

9) People who are addicted to the web struggle to function in situations that require quiet concentration and grow frustrated easily when faced with exercises that require patience.

10) People who are addicted to the web struggle to function in situations that require quiet concentration, and grow frustrated easily when faced with exercises that require patience.

11) On August 13th, 1975, my father said, "We are moving to Texas."

12) On August 13th 1975, my father said, "We are moving to Texas."

13) On August 13th 1975, my father said "We are moving to Texas."

14) My father will close his eyes, put his hands to his forehead, and breathe slowly, until he can calm his temper.

15) My father will close his eyes, put his hands to his forehead, and breathe slowly until he can calm his temper.