The early teletext decoders consisted of large metal boxes - wire-wrapped prototypes.

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Dr Hondou examined mobile-phone usage in enclosed spaces such as railway carriages, buses and lifts, all of which are, in essence, metal boxes.

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As the situation in the north remained volatile, however, the rescue operation continued for three months after the rebel withdrawal, until 2, 400 metal boxes containing an estimated 285, 000 manuscripts had been delivered to private homes in the capital.

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On one workbench wires pour out of a metal container the size of two shoe boxes.

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Kiltow often accompanied his father, helping him with the lightweight items, such as cardboard boxes, and collecting scrap metal and rags for recycling.

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The boxes were broken open for any mail to be retrieved, then metal plates were placed in the apertures, she said.

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