This particular website has this free nutrient analysis On the website people may choose to get involved in and there may be charges for those things, I don't really know, but there may be and then they may ask you for identifying information, but it's your option to do that.

网站的营养分析服务,在该网站,人们可以选择使用其他服务,当然,那些可能是收费的,我不是很确定,可能有收费服务,并要求验证个人信息,但这由你自己选择

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

And I can find the orientation of the arrow You have the option of either working with the two components of A or with the arrow.

我也可以求得矢量的方向,你可以选择使用,A 的两个分量或者矢量图来计算

耶鲁公开课 - 基础物理课程节选

So, sometimes you'll find the Rydberg constant in different forms, but just make sure you pay attention to units because then you won't mess them up, because this is in inverse seconds here, the other Rydberg constant is in joules, so you'll be able to use what you need depending on how you're using that constant.

有时候你们会发现Rydberg常数,会写成不同的形式，但你们要注意,它的单位就不会弄错了，因为这里是秒的倒数，而另一个Rydberg常数是焦耳，所有你可以根据你要怎么使用,这个常数来选择你需要的常数。

麻省理工公开课 - 化学原理课程节选