js获取页面文字的例子

请看： 目前可在IE FF，chrom运行
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function dictionary(){

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Economics
Cloud computing users avoid capital expenditure (CapEx) on hardware, software, and services when they pay a provider only for what they use. Consumption is usually billed on a utility (resources consumed, like electricity) or subscription (time-based, like a newspaper) basis with little or no upfront cost. Other benefits of this approach are low barriers to entry, shared infrastructure and costs, low management overhead, and immediate access to a broad range of applications. In general, users can terminate the contract at any time (thereby avoiding return on investment risk and uncertainty), and the services are often covered by service level agreements (SLAs) with financial penalties.[22][23]

According to Nicholas Carr, the strategic importance of information technology is diminishing as it becomes standardized and less expensive. He argues that the cloud computing paradigm shift is similar to the displacement of frozen water trade by electricity generators early in the 20th century.[24]

Although companies might be able to save on upfront capital expenditures, they might not save much and might actually pay more for operating expenses. In situations where the capital expense would be relatively small, or where the organization has more flexibility in their capital budget than their operating budget, the cloud model might not make great fiscal sense. Other factors having an impact on the scale of potential cost savings include the efficiency of a company's data center as compared to the cloud vendor's, the company's existing operating costs, the level of adoption of cloud computing, and the type of functionality being hosted in the cloud.[25][26]

Among the items that some cloud hosts charge for are instances (often with extra charges for high-memory or high-CPU instances), data transfer in and out, storage (measured by the GB-month), I/O requests, PUT requests and GET requests, IP addresses, and load balancing. In some cases, users can bid on instances, with pricing dependent on demand for available instances.[citation needed]

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