A：京广线﹣陇海线﹣京沪线﹣沪杭线
B：京广线﹣浙赣线
C：京九线﹣陇海线﹣京沪线﹣沪杭线
D：京沪线﹣沪杭线
Some students spend ________ time on the Internet. They forget to study, eat and sleep. They can't even communicate with people in real life.
