An atmosphere composed of a cold gas mix that is lighter than helium and not much heavier than hydrogen, means that hot-air ballooning will need to be used.
一个由寒冷气体混合比氦要轻但是不会比氢重很多的大气层,意味着热气球将需要使用。
3
By making the thick glass bottles invented by Dom Perignon lighter, champagne makers will save some 8,000 metric tons of greenhouse gas pollution per year with future vintages.