00:14 duration 14 seconds
水分子
說明水分子是由氫原子和氧原子組成的。
20:04 duration 20 minutes 4 seconds
Air and Burning (English subtitles available)
This programme is divisible into 5 parts as follows: 1. Composition of Air Under room temperature and pressure, air is in the gaseous state, but it can be turned into the liquid state through…