a soft yellow malleable ductile (trivalent and univalent) metallic element; occurs mainly as nuggets in rocks and alluvial deposits; does not react with most chemicals but is attacked by chlorine and aqua regia
同义词：goldatomic number 79
a unit of length used for distances within the solar system; equal to the mean distance between the Earth and the Sun (approximately 93 million miles or 150 million kilometers)
同义词：Astronomical Unit
英汉双解大词典
au
1.
the INTERNET DOMAIN NAME for（）
the INTERNET DOMAIN NAME forAustralia 澳大利亚