Use of English PRO

Sleep has (0) BECOME the Shangri-La of modern times. Amid deadlines, demands and distractions, getting eight hours is (1) ............ to finding a mythical paradise. But a good night's sleep may not be as (2) ............ as it seems. All you need to do is (3) ............ your smartphone for a tent. A new study by US scientists has found that camping can help us sleep better and reset our body clock. A group of five people were sent into the mountains for six days with no gadgets, not even torches. The campers (4) ............ up nearly 10 hours sleep each night, almost three hours longer than they were used to getting at home. Our bodies (5) ............ time using our internal clock, releasing the sleep hormone melatonin when it's time to rest and cortisol when it's time to wake. Traditionally, the sun has (6) ............ our waking and sleeping system - as the sun rises melatonin production drops off and cortisol production goes up. But less natural light and more computer light (7) ............ the body's circadian rhythm (our biological clock) and (8) ............ up sleep.