短語(yǔ)詞組短語(yǔ)twofold purchase 雙倍復(fù)滑車(chē)twofold advantage 雙重好處twofold classification 雙重劃分twofold action 雙重作用twofold integration 二重積分twofold whirl 復(fù)合旋流twofold integral 二重積分twofold connotation 兩重涵義 返回 twofold