So by looking at things like clusters of galaxies, and how they -- their number density, how many there are as a function of time -- we can learn about how dark matter and dark energy compete against each other in structure forming.
通过看这些星系的星系团， 以及它们如何----它们的数密度--- ---它们的数量以时间为函数， 我们可以了解暗物质、暗能量 如何在结构的形成上互相竞争。