Virtual channel is normally a connection from one source to one destination, although multicast connections are also permitted. The other name for virtual channel is virtual circuit.
Deep sea animals cannot produce food as there is no light. They have to depend upon the fall out of organic debirs raining down on them from surface layers. Hence they are detritivores.
Good customer service means having thorough knowledge of your inventory, experience with your products, and being able to help customers make the best choices for them.