Arc of action
[機] 作用弧
?? 詞語組成解析
arc
[ɑ:k]
n. 綜合癥狀;弧（度）;天穹;電弧，弧光。;
vi. 形成拱狀物;循弧線行進;
abbr. American Red Cross. 美國紅十字會;
of
[?v]
prep. 關于;屬于…的;由…制成;
aux. 助動詞 [非標準用語、方言] =have [主用于虛擬語氣];
action
['?k??n]
n. 行動，活動;功能，作用;手段;[法]訴訟;
??? 情景例句
I can't make up my mind about it.
關于那件事，我還不能做決定。
Have you marketed your product yet?
你們的產品尚未推出市場嗎？
the man sadly picked up the mattress and carried it into his house.
傷心地撿起了床墊，把它拿進了屋。