This is Mary's family. After dinner, Mary's mother talks on the phone. Mary's father watches TV. Mary's grandfather reads books. Mary's brother draws a picture. Mary plays with her teddy bear. They are a happy family.

⑴Mary's mother ____          A.

⑵Mary's father ____           B.

⑶Mary's grandfather ____      C.

⑷Mary's brother ____         D.

⑸Mary ____                 E.

解分式方程：$\frac{3}{x^2-9}$﹣$\frac{x}{3-x}$=1．

绿色开花植物跟人体结构层次相比较，没有的结构层次是（    ）

人的情绪是多种多样的，我们应选择适当的场合表达自己的情绪，因为（    ）