Xy Well, what is v? v is xy.

什么是v？，v就是。

Let the line AB be equal to the line XY.

假设AB线与XY线相等.

So, that means I keep xy equals constant.

这也就意味着我将把xy当作常数。

Draw a square with the line XY as its base.

以直线“XY”为基线画一正方形。

For humans, that system is a genetic XY system.

对人类而言，这套系统是遗传的XY系统。

Male have XY chromosome. Female have XX chromosome.

雄性动物细胞有一对XY染色体, 雌性动物细胞有一对XX染色体.

Fx=2xy The first thing we will do, we know that f sub x is 2xy.

首先，我们知道。

Xy: The good guys are taking too long to get down here.

善良的家伙们下来这里花的时间太长了。

The cells of a male body one X and one Y chromosome ( XY ).

男性体细胞则含有一个X和一个Y染色体 ( XY ).

So, for that, I will choose some region in the xy plane.

我会选择xy平面内的一个区域。