Solutions exist for airplane emissions, ranging from low-carbon biofuels to more efficient engines and lighter plane bodies.

我们还是有解决飞机排放问题的方法的，比如使用低碳生物燃料、增强引擎效率以及减轻机身重量等。

If the heavier of the two bodies generating the points has less than 25 times the mass of the lighter body, these points are too unstable to park things in.

如果两个天体中较重的天体质量不足较轻天体的 25 倍，这些点就会不稳定，物体无法在其中停靠。

You want your body, the part that's moving to weigh at least as much as the foot and when your body's lighter it's basically this collision this energy transfer is very inefficient and you don't jump very high.

你希望你的身体，移动的部分至少与脚一样重，当你的身体较轻时，基本上是这种碰撞，这种能量传递非常低效，你不会跳得很高。