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)________ anything between two and five hours' sleep a night less than their parents did at their age.
Điền vào số 4
A. or
B. because
C. whereas
D. so
Đáp án C
Giải thích: 2 ý này trái ngược nhau nên e dùng từ whereas để nối.