trass的翻译，读音
英/træs/
释义：
n. 火山灰
n. A white to gray volcanic tufa, formed of decomposed
trachytic cinders; -- sometimes used as a cement. Hence, a coarse sort
of plaster or mortar, durable in water, and used to line cisterns and
other reservoirs of water.
n. A white to gray volcanic tufa, formed of decomposed
trachytic cinders; -- sometimes used as a cement. Hence, a coarse sort
of plaster or mortar, durable in water, and used to line cisterns and
other reservoirs of water.