一旦杂质沉淀下去，油就可以分级了。Once its impurities had settled, the oil could be graded.将硫酸盐加入该溶液会产生沉淀.Adding sulphate to the solution will give a precipitate.渣滓沉淀在容器的底部.Dregs settled at the bottom of the container....
The long food line curled from some courtyards into the street.领食物的长蛇阵从有些院子里蜿蜒到街道上.Here were crumbling tenements, squalid courtyards and stinking alleys.随处可见破烂的住房 、 肮脏的庭院和臭气熏天的小胡同.London's financial district is full...