3. Avoid hard-to-read color combinations such as red/green, brown/green, blue/purple. Aim for high contrast between the background and text.

3. 避免看起来费力的颜色组合，比如红/绿，棕/绿，蓝/紫。尽量让背景和文字的对比明显。

He programmed his computer to compare the 1,431 possible combinations of pairs in this population.

他给他的计算机编了程来比较这些人中1431种可能的成对组合。

Native speakers can distinguish between grammatical and ungrammatical sentences even when they have never heard particular combinations before.

母语使用者可以分辨符合语法规则和不符合语法规则的句子，即使他们以前从没有听过这些特定的词语组合。

Researchers claim that a new quiz is able to work out your personality type on the basis of how you react to a series of colour combinations.

研究人员声称，有一项新的测验能够根据你对一系列颜色组合的反应来确定你的个性类型。

Isoquant curve is a line showing all the alternative combinations of two factors that can produce a given level of output.

等产量线是表示两种生产要素的不同数量组合可以带来相等产量的一条曲线。

Some combinations are below.

一些组合如下所示。