Debby’s son, Mark, is a junior high school student. He
spends much time playing games on his cellphone everyday. At
first, she didn’t worry about    it    until she got a note from his
teacher.
      Mark does not talk to his classmates anymore during
break time. When the bell rings, he takes out his phone and
starts playing games. He doesn’t stop until the teacher tells
him to do so. He plays them when he is eating, doing his
homework, and even walking on the stairs.
      Today Debby got his phone bill----NTS10,000. She was so
angry and worried. Then she went online and saw the chart on
the bottom. She found Mark is the same as many young
people at his age.
* until 直到 / stair 階梯
44. What is the main idea of this reading?
(A) Cellphones are important for young people.
(B) Debby can’t understand the chart.
(C) Young people spend lots of time playing online games.
(D) Debby’s son uses his cellphone for too many hours.