A DID system can be used for fax and voice mail as well as for live voice connections. Compared to regular PBX service, DID saves the cost of a switchboard operator, calls go through faster, and callers feel they are calling a person rather than a company.
Key Concepts: In dicotyledonous leaves there are two types of mesophyll cells, palisade mesophyll and spongy mesophyll. Palisade mesophyll cells form a layer beneath the upper epidermis whereas spongy mesophyll cells are internal to the lower epidermis.
These are the major tissue types in the human body: â¢Connective â¢Epithelial â¢Muscular â¢Nervous system â¢Lymphatic Connective Tissue Connective tissue is made up of cells and protein fibers and provides support for other body tissues. The main proteins in connective tissue are collagen and elastin.