Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 31 to 35.

   Why is it that many teenagers have the energy to play computer games until late at night but can’t find the energy to get out of bed in time for school? According to a new report, today’s generation of children are in danger of getting so (31) ________ sleep that they are putting their mental and physical health at risk. Adults can easily survive on seven to eight hours’ sleep a night, (32) ________ teenagers require nine or ten hours. According to medical experts, one in five youngsters gets anything between two and five hours’ sleep a night less than their parents did at their age.

    This (33)________ serious questions about whether lack of sleep is affecting children’s ability to concentrate at school. The concentration between sleep deprivation and lapses in memory, impaired reaction time and poor concentration is well established. Research has shown that losing as little as half an hour’s sleep a night can have profound effects (34)________ how children perform the next day. A good night’s sleep is also crucial for teenagers because it is while they are asleep that they release a hormone that is essential for their “growth spurt” (the period during teenage years when the body grows at a rapid rate). It’s true that they can, to some (35) ________, catch up on sleep at weekends, but that won’t help them when they are dropping off to sleep in class on a Friday afternoon.

According to a new report, today’s generation of children are in danger of getting so (31) ________ sleep that they are putting their mental and physical health at risk.