created sense approved 标砖/標磚 · biāozhuān · keystone
标砖 / 標磚
biāozhuān
keystone
the central brick or stone at the top of an arch that holds the structure together
这块标砖被嵌入拱顶，加固了整个建筑。
created sense approved 标砖/標磚 · biāozhuān · marker brick
标砖 / 標磚
biāozhuān
marker brick
a brick used as a reference point for alignment or leveling in building construction
工人在砌墙时先放好标砖以确保水平。