1. Each layer of color represents an eruption. ��һ����ɫ�ʹ���һ���緢��
2. The first is the management and operation of layer be resistance. �����ǹ�����Ͳ������Ϊ��ҵ��չ��������
3. The access layer provides users in workgroups access to the network. ��ȡ���ṩ����Ⱥ����û�����ʹ����·��
ӢӢ����
n.
1. single thickness of usually some homogeneous substance
2. a relatively thin sheetlike expanse or region lying over or under another
3. an abstract place usually conceived as having depth
4. a hen that lays eggs
5. thin structure composed of a single thickness of cells v.
1. make or form a layer