first approximation

基本解释

That, to a first approximation, is the neo-Darwinian account of how phenotypes evolve.
以上基本就是新达尔文主义关于表型进化的观点。
This approach is mathematically a first approximation to messages with a variable size (bear with me, I will keep it short and simple ).
这个方法在算术上最接近大小不定的消息（请原谅，我将尽量使它简短）。
So the first approximation is, you can realize that the molar volume of the gas is always much bigger than the volume of the solid or the liquid.
第一个近似是，你会发现气体的摩尔体积,远远大于固体,和液体的摩尔体积。

While these gas molecules or atoms through first approximation, are like hard spheres.
可以看做刚性小球,每一个分子会占据。
麻省理工公开课 - 热力学与动力学课程节选
What we've learned so far is as a first approximation, what we want to do is put the atom with the lowest ionization energy in the middle here.
我们之前所学的可以作为第一近似，我们要做的是把电离能,最低的原子放在中间。
麻省理工公开课 - 化学原理课程节选
It's always a good first approximation, because you need to start somewhere in terms of drawing Lewis structures, but then if you go and figure out the formal charge and you just have lots of charge separation or very high charges, like a plus 2 and a minus 2 and a minus 1 all different places in the atom, what it should tell you is maybe there's a better structure.
它总是一个好的第一近似，因为在画路易斯结构的时候,你总需要一个起点，但是如果你在算出形式电荷之后,发现有很多电荷分开了,或者说有很高的电荷，比如有一个正二，一个负二，还有一个负一1,在原子的各个地方，这应该就是在告诉你,或许还有一个更好的路易斯结构。
麻省理工公开课 - 化学原理课程节选

And there's a debt that goes up so on a first approximation, the tax cut doesn't cut away from that.
NPR: Wall Street Woes: Who Gets A Bailout?