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LONGER SLEEP
Scientists believe that the ‘body clock’, which manages the cycle of sleep and wakefulness, changes
in adolescence. (...)

(Cała treść tekstu, z uzupełnionymi lukami, została skopiowana do odpowiedzi.)

A. A change in school hours would be beneficial to teenagers, but it would take a massive campaign for it to happen.
B. But there was not enough “hard evidence” to justify the “drastic step” of changing the schedules.
C. According to them, adequate sleep is the strongest factor in the wellbeing and mental health of teenagers, and any shortage is linked to poor educational results, anxiety and obesity.
D. The sleep-wake rhythm shifts by two hours in teenagers, which means that they are wired to go to sleep and wake up later.
E. It followed the publication of a study of teenagers in Seattle which found a “significant improvement in the sleep duration of students” when the start of the school day was delayed by almost an hour.