With difficulty he released the mattress from the metal frame, and groped beneath it.

他费了很大劲把床垫从金属架上卸下来，然后在下面摸索一番。

《柯林斯英汉双解大词典》

The frame is made of metal.

框子是用金属做的。

《牛津词典》

The procedure involves an artificial aortic valve, made from pieces of a cow's valve sewn to a metal frame.

该过程涉及到使用一只人工制作的主动脉瓣，它是由一个缝在金属框架里的牛的脉瓣制成的。

youdao

A hoop house is basically a metal frame covered with plastic or other all-weather material.

VOA: special.2009.12.22

His father, Ravi Pazhani, a slight man with metal-frame glasses, sat behind him.

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The original Zeppelins were based on a rigid design in which separate gas-tight compartments were surrounded by a metal frame covered with a non-airtight fabric.

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And added a Metal Works-special top frame with duplex-style front bars.

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