The next question is why the glass casing surrounding an electric light might be compared to an onion.

下一个问题就是，为什么人们会将电光外的玻璃罩类比成洋葱？

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The glass casing of the iPhone 4 and iPhone 4S made it less prone to scratches, though it was susceptible to cracks.

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To prevent damage to the camera's lens, a resin ring as been added around the glass casing to ease shocks to the lens area.

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The glass front is entirely flat, and sits flush with the polycarbonate casing -- unlike the slightly protruding, curved screen edges of the 8X.

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