下列说法中正确的是       （     ）

①逐步摆脱对父母和老师的依赖，学会自主学习                     ②自己喜欢的科目就认真对待，不喜欢的科目就不闻不问

③科学安排时间，制定学习计划，努力提高学习效率              ④完全听从老师和家长的吩咐，他们怎么说，就怎么做

    It's 10:00 on Saturday morning. What are the students doing in different countries?

Zhao Tao, China

    He's a boy from Dalian, China. He is doing his homework at home. He wants to play basketball with his friends, but he can't. He has a lot of homework to do on Saturday.

Julia, America

    She is 13 years old. She is from Hawaii(夏威夷). Hawaii has the best beaches. Now she is lying on the beach and listening to music.

Lisa, Britain

    Now she is taking Rick, her pet dog, to the hospital, because he is sick and needs to see a doctor. So she can't go to the movies with her friends.

Dave, Japan

    He is a 15-year-old boy. He is playing football with his friends. He palys it very well. And he is the captain(队长) of the school football team

分数 $\frac{4}{x}$ ，当x____时是真分数，当x____时是假分数。