阻塞控制最好由OSI协议的哪一层控制（）。
A.数据链路层
B.会话层
C.传输层
D.网络层
参考答案：B
— Is Lucy or Lily the ______ of the twins?
— Lucy. She was born half an hour earlier. [ ]
A. younger
B. youngest
C. elder
D. eldest
天棚装饰面积，按主墙间的净面积计算。
