英语语法分析

We could also add rollaway.

我们还可以加活动床铺。

Arc rollaway, on which several steel ball are set, is set on convex ball surface of inner ring.

沿内圈的凸形球面上设有两条弧形沟道，在弧形沟道上设有若干钢球。

Same with "Rollaway Bed" (R. W. B) A portable single bed which can accommodate an additional guest.

加床：与“可移动床（R.W.B）”同义。一只可移动的单人床，可供另一客人使。