In moments of war there's great technological innovation, and in the world you have to do without -- well, during the Second World War, you had to do without steel, you had to do without aluminum.
在战争年代，技术创新层出不穷。 但是在物资匮乏的社会里，比如在二战时期， 你得面对没有钢铁 没有铝的情况。