Fill in the Blanks (Reading & Writing)

Choose the word that best fits each blank.

Sleep is far from a passive state in which the brain simply switches off. During the night, the brain cycles through several distinct stages, each thought to serve a different function. In the deepest stages of slow-wave sleep, the body repairs tissue and the brain appears to clear away waste products that accumulate during waking hours. During rapid eye movement sleep, by contrast, the brain becomes highly active and is believed to consolidate memories, strengthening the connections that store what we learned during the day. Researchers have found that people deprived of sleep struggle to retain new information, suggesting that a good night's rest is not a luxury but a biological necessity for learning. Chronic shortage of sleep has also been linked to weakened immunity and impaired concentration.

Sleep is not a —passivenecessaryactive state: during slow-wave sleep the brain clears away waste, while during rapid eye movement sleep it helps —consolidateeraseignore memories, which is why people who are deprived of sleep find it hard to —retaindiscardcreate new information.