Underlying = inner (underlying adj.在下面的, 隱含的 ，implicit 如 underlying meaning)
    underpinning (基礎(chǔ), 支柱, 支撐 a support or foundation)
    Unqualified (不合格的，無限制的，絕對的) = complete
    utilitarian = functional (文中選) (utilitarian adj.功利的, 實利的, 功利主義的 n.功利論者 )
    unqualified =complete;
    utilitarian =functional
    universally--without exception
    unrestricted--unlimited
    undergone--experienced
    uniform
    vigorous = strong
    vexing = difficult (not sure) (vex: 使惱怒，使痛苦, puzzle, annoy)
    volatile--
    vast--immense
    vast--great
    vehicle--means
    variability==tendency to change
    withstand==persist >avoid/persist? 原文是：...brick withstood the weathering for a long time...
    withstand=resist
    wear--use
    whatever --in any case/ at any rate/at all event
    wary--cautious
    way station--stop
    ？= yet 選項還有however / in addition.
    yield--provide