The tying of bow ties is an art; the untying is easy.打领带是一种艺术, 解领带则很容易.As they were untying the colt , its owners asked them, " Why are you untying the colt ? "33他们解驴驹的时候, 主人问他们说, 解驴 驹 作 什么 ?Some of the bystanders were s...
最具有经济价值的铁矿包括磁铁矿和赤铁矿.Iron ores of greatest economic interest contain magnetite and hematite.A-Fe2O3(赤铁矿 ) 是中子衍射最先研究的化合物之一.A - Fe 2 O 3 ( haematite ) was one of the first compounds to be studied by neutron diffraction.发现一种...