A、The rapid growth of the service sector of the world economy. B、The invention of the computer. C、The rapid growth of the world

Office systems are equipment used to create, store, process, or communicate information in a business environment. This information can be manually, electrically, or electronically produced, duplicated, and transmitted.
    The rapid growth of the service sector of the world economy beginning in the mid-1970s has furnished a new market for sophisticated office automation.
    Most modern office equipment, including typewriters, dictation equipment, facsimile machines, photocopiers, calculators, and telephone systems as well, contains a microprocessor. With the increasing incorporation of microchips into office equipment, the line between the computer and other equipment has blurred.
    At the same time, computers, either stand-alone or as part of a network, and specialized software programs are taking over tasks such as facsimile transmission or fax, voice mail, and telecommunications that were once performed by separate pieces of equipment. In fact, the computer has virtually taken the place of typewriters, calculators, and manual accounting techniques and is rapidly taking over graphic design, production scheduling, and engineering design.
    The use of computers and other modern equipment has enabled links to be established far beyond the walls of a building. Electronic links allow people in a modern office to communicate with workers at home or in satellite offices. This capability has led to a sharp increase in telecommunicating. Since the early 1990s workers have worked at least part of the time outside the main office. Managers and professional employees are the major participants in this trend. As they no longer have to spend hours traveling from home to office, their work productivity has increased.
    As technology advances further, new equipment will be invented and introduced into the modern office, which will result in even greater efficiency in office work.