So, if we're going to go to the moon, we're going to go to Mars,we want to be able to produce oxygen, structural metals and photovoltaic materials from in situ resources.

如果我们要去月球上，我们要去火星上，我们则必须要制造,氧气，结构金属和光电材料,就在原地制造。

麻省理工公开课 - 固态化学导论课程节选

So you don't have ductility, which is what you have in metal.

所以材料不具备延展性，而且金属中有自由电子。

麻省理工公开课 - 固态化学导论课程节选