The average response time for people with names beginning with one of the last nine letters of the alphabet, R through Z, was 19.38 minutes.

那些姓氏首字母排在字母表中后9位（即R-Z）的人，他们平均的反应时间为19.38分钟；

youdao

Of course, r goes all around the z axis, but I'm just doing a slice through one of these vertical half planes, fixing the value of theta.

当然，r可以围绕z轴转圈，但我只做了一个垂直的半平面，对于一个确定的θ来说。

youdao

How do we get rid of z? Well, if we are on the top surface, z So, I plug z equals z2 of x, y into the formula for R, whatever it may be.

怎样才能消去z？，考虑顶部曲面，通过函数z2给出。，z，is，given，by，this，formula，，z2，of，x，，y。,所以我把z=z2代入到R中，不管是什么。

youdao

So instead of being equal to negative z squared, now we're equal to negative z effective squared times r h all over n squared.

这里不再等于-z的平方，现在我们等于-有效的z的平方,乘以RH除以n的平方。

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