当股票价格守护程序发布更改时，将通过系统帐户通知每个侦听器，但仅在侦听器的安全上下文中进行通知(图4)。
When the stock price daemon publishes the change, using a system account, each listener will be notified, but in the listener's security context (Figure 4).
如果信用卡被成功验证，并且这些钱也成功地从用户帐户中转出，在线股票交易应用程序就会从市场购买所需的股票数。
If the credit card is validated successfully and the funds are successfully transferred from the users account, the online application buys the required number of stocks from the market.
你把钱存入帐户，好比是一个开放式股票基金，每年平均给你10%的现利。
You put the money into an account, like a stock mutual fund, that gives you 10% per year interest on average and presto.
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