Fourau富罗fournum.四four-conductor cable四导线电缆Fourier representation傅里叶表示法four turns electdc car四轮电动车four pole double throw四极双掷four fundamental rules四则运算four-wheel alignment四轮定位four-constraints fit四约束条件拟合Fourier transformation傅里叶变换,傅里叶转换,傅理叶变换four-branch taxonomy四部分类法four-dimenslon whole四位一体