翻譯P.28

Some matter consists of one element ,but most matter consists of compounds : combinations of two or more different elements held together in fixed proportions. For example, water is a compound made of the elements hydrogen and oxygen, which have chemically combined with one another.
一些物質由一種元素組成，但是大多數物質由化合物組成︰ 兩種或更多不同的元素在固定的比例結合在一起。 例如，水是由元素氫和氧組成的化合物，是已經和另一個化學的結合。