A:watching him to eat so quickly
B:watch him eat so quickly
C:watching him eat so quickly
D:to watch him eat so quickly
①计算所用浓硫酸的体积 ②量取一定体积的浓硫酸 ③稀释、冷却 ④转移、洗涤 ⑤定容、摇匀.
回答下列问题:
当a>l时,函数f (x)=logax和g(x)=(1﹣a)x的图象的交点在( )
加热10.0g碳酸钠和碳酸氢钠的混合物至质量不在变化,剩余固体的质量为8.45g,求混合物中碳酸钠的质量分数.