Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 31 to 35.
Insomnia is almost twice as common in women as in men, but even those who feel they haven't slept a wink probably have had more sleep than they think. Nowadays we believe that we need to get eight hours' uninterrupted sleep; but in the Middle Ages, people would often get up for a while in the night, wide awake, to chat or even visit neighbours. However, it is true to say that having artificial light sources has meant that we tend to get less sleep overall than we used to.
According to recent research, nearly half of US adults admitted to falling asleep unintentionally during the day at work, on public transport or, worryingly, while driving. Twice as many men as women admit to nodding off while driving. In many cultures, having a snooze (though not while driving!) is much more culturally acceptable than in the US, and it might help to make the roads safer. Apparently, a short nap is more refreshing than a cup of coffee.
Once parents stop managing their bedtimes, teenagers usually start going to bed much later. However, because their brains are still developing, they still need between nine and ten hours a night, as much as a sixyear-old. Late-night studying, however, does have some advantages, as there is vidence that sleeping when you've just learnt something new will help your memory to retain it. 80% of people need between six and nine hours' sleep a night. But if you are used to sleeping like a log for nine hours, can you force yourself to get used to having only six? Apparently not, but you an catch up on missed sleep by having a lie-in, and it even works if you have the lie-in on the morning before you miss the sleep.
