自1951年以来，在职的已婚女性的比例已经从刚超过五分之一增长到二分之一。

Since 1951 the proportion of married women who work has grown from just over a fifth to a half.

youdao

而这一比例在未参加产前培训的妈妈中为二分之一。

This compared with half of mothers who did not attend classes.

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日本企业的净资产收益率达到5%左右，是欧洲企业的二分之一以及美国企业的三分之一。

Japanese firms have a return on equity of around 5%, which is half that of European companies and a third that of American ones.

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So, shared electrons are the ones that are shared between the carbon and the nitrogen, so we have 6 shared electrons, and we want to take 1/2 of that.

共用电子是那些在碳和氮之间,被它们共用的电子，那么我们有六个共用电子，然后我们要给它乘上二分之一。

麻省理工公开课 - 化学原理课程节选

If I pick an angle of 60 degrees, these are some numbers like half and root 3 over 2.

要是我选择一个 60°的角,上面的系数就会是二分之一和二分之根号三

耶鲁公开课 - 基础物理课程节选

Then minus 1/2 of 2, because we only have one bond or 2 electrons in a bond.

然后减去二的二分之一，因为我们只有一个键，一个键就是两个电子。

麻省理工公开课 - 化学原理课程节选