Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the word or phrase that best fits each of the numbered blanks.
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 ___(1)___ for school? According to a new report, today's generation of children are in danger of getting so ___(2)___ sleep that they are putting their mental and physical health at ___(3)___. Adults can easily survive on seven to eight hours' sleep a night, ___(4)___ teenagers require nine or ten hours. According to medical experts, one in five youngsters ___(5)___ by on between two and five hours' sleep a night, less than their parents did at their age.