To do so, it will pick off the first element of the list — the head — to do the processing on that element, and recursively pass the rest of the list to itself again.

为此，它将选取列表的第一个元素 — 列表头部 — 来对该元素执行处理，然后再递归式地将列表的其余部分传递给自身。

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Is he not troubled that the first layer was a pass through, that the suspect got on the plane despite being on the list?

WHITEHOUSE: Press Briefing