加强公安队伍建设的基本工作思路是（）。

A.建设过硬班子

B.纯洁公安队伍

C.创出一流业绩

D.树立良好警风

E.提高执法水平

Communication protocols are (66) connection-oriented or connectionless, (67) whether the sender of a message needs to contact and maintain a dialog with the recipient or (68) send a message without any, prior connect and with the hope that the recipient receives everything. (69) .These methods (70) the two ways that communication is implemented on networks.

A．fulled

B．flooded

C．depending on

D．defined by