It can be made of foam, latex, coil spring, water, or even air.

它可制成泡沫，乳胶，弹簧，水，甚至空气。

youdao

It can be made of foam, latex, coil spring, water, or even air.

它可制成泡沫，乳胶，弹簧，水，甚至空气。

youdao