“举例说出脂质的种类和作用”是“细胞中的糖类和脂质”这一节的教学目标之一，该教学目标属于（）。

A.知识目标

B.能力目标

C.过程与方法目标

D.情感态度与价值观目标

OSI is a theoretical model that shows how any two different systems can communicate with each other. Router, as a networking device, operate at the ______ layer of the OSI model.

A．transport

B．application

C．network

D．physical