Why is it that many teenagers have the energy to play computer games until late

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word for each of the 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 (42) ______ for school? According to a new report, today's generation of children are in danger of  getting  so (43) ______ sleep that they  are putting their  mental and physical health at (44) ______. Adults can easily survive on seven to eight hours' sleep a night, (45) ______ teenagers require nine or ten hours. According to medical experts, one in five youngsters (46) _______ anything between two and five hours' sleep a night less than their parents did at their age.

Điền vào số (45)