n.枕木
Many sleepers were fixed on a railway. 一條鐵路上有許多固定了的枕木。
Pre-stressed concrete sleepers that have been designed to replace the conventional wooden ones have been tested. 預(yù)應(yīng)力混凝土枕木用來(lái)替代傳統(tǒng)的木質(zhì)枕木并已通過(guò)了試驗(yàn)。
