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.
Non-meristematic plant tissues are classified as either simple tissues (containing only one type of cell) or as complex tissues (containing multiple types of cells) There are â¦ three types of simple tissues: 1. Parenchyma 2.Collenchyma 3. Sclerenchyma.on-meristematic plant tissues are classified as either simple tissues (containing only one type of cell) or as complex tissues (containing multiple types of cells) There are â¦ three types of simple tissues: 1. Parenchyma 2. Collenchyma 3. Sclerenchyma.