—I don't know the _______. Maybe you can ask his good friend Simon.
A:opinion
B:problem
C:reason
如果你走在北宋都城东京的大街上,从你穿戴的服饰上,可辨认出你属于士、农、工、商的哪一类。
①蔗糖 ②熔融NaCl ③盐酸 ④铜丝 ⑤NaOH固体 ⑥液态HCl⑦H2SO4⑧CO2⑨食盐水