短語詞組短語round trifoliated arch 三葉形拱round horseshoe arch 圓馬蹄形拱round d arch 半圓拱a round arch 半圓拱half -round arch 半圓拱round arch saggregation 圓頭螺絲round arch dam 圓弧拱垻Round arch or Semi -circular arch 半圓拱Arch Round bar 水曲圓棒 返回 round arch