Because it plays such a central role in the communication between the upper and lower layers of the Bluetooth protocol stack, the L2CAP layer is a required part of every Bluetooth system.
因为它在蓝牙协议栈的高层和低层通信中起着重要的作用，L2 CAP是每一个蓝牙系统必须的部分。
2
We have no need to work, the central bank to print money, each holding a large stack carried home is, what I do in this lecture?