显然, 这些生产商们知道ED与萤石之间的差别.Obviously, they know the difference between fluorite and ED.矿物质图片画廊.外观紊乱的方解石突出几何精确度的萤石.The seeming disorder of calcite highlights the geometric precision of fluorite.该氧化铈还优选具有萤石类似结构的超晶格结构.The ceriu...
Usefulness includes the fact the negatives have been calibrated.所谓有用,是指在底片上要有标度.The theory is of limited usefulness.这个理论用途有限。The report is of potential usefulness to the government.这个报告可能对政府有用。There are doubts about the ...