A service invocation is almost always a two-way operation, meaning that a request is sent from the consumer to the provider and a response is sent back in the other direction.

服务调用几乎始终是双向操作，这意味着请求是从使用者发送到提供者的，而响应是按照相反的方向返回的。

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The process contains a receive activity followed by an invoke activity, and a reply activity that is needed only if the operation offered by the process is a two-way operation.

代理流程包含一个接收活动，后面跟着一个调用活动，以及一个仅当该流程提供的操作是双向操作时才需要的应答活动。

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There are two operation choices; one-way and request-response.

可以选择两种操作类型，单向操作和请求-响应型操作。

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Operation Flamborough will assess the way officers investigated two rape claims against other students by a girl at Stanbridge Earls School, Romsey.

BBC: Stanbridge Earls School: Police to review sex claims

Olivia was then transferred to Hope Hospital to see a kidney specialist and to have an operation, but had two heart attacks on the way, and later died.

BBC: Hospital blunder poisoned baby girl

To make my point in a different way, let me sketch an analysis of the operation of two kinds of health markets: the one before World War II and the one since then.

FORBES: How To Solve The Health Care Crisis