four-fold 是什么意思

	adj.,adv. 四倍，四重。

	four times as great or many; "a fourfold increase in the dosage" 同义词：quadruple, fourfold,
	having four units or components; "quadruple rhythm has four beats per measure"; "quadruplex wire" 同义词：quadruple, quadruplicate, quadruplex, fourfold,

A molecule cannot have a three-fold axis and a four-fold axis in the same direction .
一个分子不能在同一方向上有一个三重轴和一个四重轴。

four-fold是什么意思