题目

工业上制备下列物质的生产流程不合理的是() A . 由黄铁矿制硫酸:黄铁矿 B . 由重晶石制可溶性钡盐:重晶石(BaSO4)BaCO3BaCl2(aq) C . 由石英砂制高纯硅:石英砂粗硅 SiCl4 Si D . 由铝土矿冶炼铝:铝土矿Al2O3 AlCl3(aq)Al 答案：D Shall I tell him about it?  No, you ________. I've told him already. [　　] A．needn'tB．wouldn'tC．mustn'tD．shouldn't