石灰石纯度,即石灰石中()的含量,()的含量越高,其能与SO2反应的物质就越多,脱硫效果就好,石膏的纯度也越高。
参考答案:CaCO3;CaCO3
Jamie is a young cook wants to improve school dinners. [ ]
A. who
B. whose
C. whom
D. which
染色体检查时常用的有丝分裂原是( )
A.ConAB.PHAC.美洲商陆AD.秋水仙素E.秋水仙胺