互动封闭仿真课堂1、智能交互 2、电子板书式视频教学 3、5分钟一次互动问答 4、封闭课堂
A. Because even though you are not an adult， you must deal with adult problems.
B. Because even though you are an adult， you must deal with children's problems.
C. Because even though you are a teenager， you must do a lot of homework.
D. Because adults often make them feel stressed.
2. Families can add to the stress a teenager might experience ______.
A. by asking them to go to university
B. by helping them with their homework
C. as teenagers quarrel with their parents， and their brothers or sisters
D. as families never support their children enough