上下铺的床 meaning in Chinese

bunkbed frame

I overheard their conversation , and it seemed that the mother wanted to buy a double - decker bed for the children . but they would soon be moving , and if they made the purchase that day , they would have to pay transportation charges again when they moved . besides , the bed would have to be dismantled and then reassembled
我在旁边听到他们之间的谈话，好像是那位妈妈想要买一组上下铺的床给那两个小孩，但因为他们很快就要搬家，如果现在买回去的话，下次搬家的时候还要再付一次床的搬运费，而且必须把床拆开，搬到新家后再组装回去，由于要多花钱，所以那位妈妈不想现在买。