Now, to solve this equation, we'll first cross multiply.

要解这个方程，我们先交叉相乘。

Before they are safe in Kenya, the animals must first cross the Mara River.

在它们安全到达肯尼亚之前，那些动物必须先过马拉河。

It is not always equal in degree in a first cross and in the hybrids produced from this cross.

在第一次杂交和由该杂交产生的杂种中， 其程度并不总是相等的。

No matter how much research you do prior to your first cross cultural negotiation communication road blocks can easily come up.

无论你在第一次跨文化谈判之前做了多少研究，沟通的障碍都很容易出现。

So that here we have perfect, or even more than commonly perfect fertility, in a first cross between two distinct species.

因此，在两个截然不同的物种之间的第一次杂交中， 我们在这里拥有完美的， 甚至比通常更完美的生育能力。

First crosses between forms, sufficiently distinct to be ranked as species, and their hybrids, are very generally, but not universally, sterile.

形式之间的首次杂交， 足以区分为物种，以及它们的杂交种， 通常是不育的， 但不是普遍的。

I think I first crossed the border into the world of economics either my last year of graduate school or my first year as an assistant professor.

我想我是在研究生院的最后一年或作为助理教授的第一年第一次跨界进入经济学世界的。

In treating this subject, two classes of facts, to a large extent fundamentally different, have generally been confounded; namely, the sterility of species when first crossed, and the sterility of the hybrids produced from them.

在处理这个问题时， 两类在很大程度上根本不同的事实通常被混淆了；即，物种首次杂交时的不育性， 以及由它们产生的杂交种的不育性。

By a reciprocal cross between two species, I mean the case, for instance, of a female-ass being first crossed by a stallion, and then a mare by a male-ass: these two species may then be said to have been reciprocally crossed.

所谓两个物种之间的相互杂交， 我指的是母驴首先与种马杂交，然后母马与公驴杂交的情况：这两个物种可以说是相互杂交的.