3 | Watch the first part of the video and complete the gaps.

N1 stage: | ► | People don't know the difference between being 1) ★★★ and being 2) ★★★. Lasts from 3) ★★★ to 4) ★★★ minutes.

N2 stage: | ► | Brain activity, 5) ★★★ and the respiratory rate slow down. Lasts from 6) ★★★ minutes to as long as 7) ★★★.

N3 stage: | ► | This stage is called 8) ★★★. Helps restore your 9) ★★★ and 10) ★★★.

N4 stage: | ► | In the REM stage, your brain is very 11) ★★★ Brain cleans up 12) ★★★.

All these stages last 13) ★★★ and can repeat 14) ★★★ times in one sleep cycle.

4 | Watch the second part of the video and correct the mistakes in the sentences. There are mistakes in each sentence.
1. Normally, naps last between 13 and 90 minutes. 2. Power nap lasts between 12 and 30 minutes. 3. You will feel relaxed if you nap for a long time. 4. Power nap is successful when you enter deep or REM sleep. 5. If you nap too early, you might have problems at night. 6. The best time for a power nap is known as the breakfast dip. |

5 | Discuss the questions with a partner. • Why is it important to get a good night's sleep? • How many hours do you normally sleep per night? • How do you feel if you don't sleep well at night? • Do you like napping? Why or why not? |

6 | Project work. Choose one of the given topics and prepare a group presentation.

Delta waves sleep | Tips for falling back to sleep | Tips for better sleep