这里正在进行一个双向的学生交换活动。

Here is a two-way student exchange in action.

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双向的，它们能够进行事件处理和请求处理。

Bidirectional, in that they are capable of event processing and request processing.

youdao

如果没有对已有源代码的可视化或者获取模型的—并且没有对之前被识别的代码进行合并，就不会有双向工程的概念。

There is no visualization or harvesting of models from existing source code — and without a merge as identified previously, there is certainly no notion of round-trip engineering.

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