—Your grandmother looks quite ________ today, doesn't she?

—Yes. She told me she slept much ________ last night.  [ ]

A. good, well

B. well, good

C. well, better

D. good, better

将铁和氧化铁的混合物15g加入150mL稀硫酸中，在标准状况下放出氢气1．68L，同时铁和氧化铁均无剩余，向溶液中滴加硫氰化钾溶液后，未见颜色变化，为了中和过量的硫酸，而且使铁完全转化成

Fe(OH)₂，共消耗3mol/L的NaOH溶液200mL。则原硫酸溶液的浓度_____________。