That basic slip joint set the evolutionary stage for a further modification: the cocking slip joint.

这个基本的滑动接头为进一步的改进奠定了进化阶段：竖起滑动接头。

In the first evolutionary stage, which we're currently in, planet-based fuel sources like fossil fuels, solar panels, and nuclear power plants are probably enough to settle other planets inside our own solar system, but not much beyond that.

在第一个进化阶段，也就是我们现在所处的阶段，基于行星的燃料资源，比如化石能源，太阳能电池板和核电站也许足够让我们在太阳系内其它星球上定居，但也仅此而已。