One gets a contribution from an electron outside closed shells and also a possible contribution coming from an incomplete shell or a hole in a closed shell.

化学键的形成来源于一个满壳层之外的电子，也有可能是形成于一个不完全的壳层或满壳层上的一个电子空穴。

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First the shell begins to crack. Then there's a flurry of activity as the tiny creature curled up inside the egg breaks a hole in the shell.

首先是蛋壳开始裂开，一阵小小的骚动以后，蜷缩在蛋壳里的小生灵在壳上啄开一个洞。

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Shell has been trying to spend its way out of that hole by running the industry's biggest capital budget of $30 billion to $33 billion a year.

壳牌甚至通过行业内最大的年度预算——300亿到330亿美元，来试图弥补这个巨大的丑闻漏洞。

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You might fall into a flooded shell hole, and you would drown because you couldn't get out.

BBC: Survey begins in bid to preserve WWI trenches in Edinburgh

The Brent Spar platform was obsolete and after evaluating options and conferring with the UK government, Shell announced the company would blow a hole in it and sink it to the bottom of the ocean.

FORBES: Part I in a CSR Series: Corporate Citizenship in a Global Economy

This is done by pricking a hole in a compartment's acrylic shell with a laser.

ECONOMIST: Cataracts