Trình bày phương pháp hóa học phân biệt các dung dịch không màu sau : KOH ,K2CO3 , Na2SO4 , NaNO3

A new apartment building ....in the suburb now A was built B built C is built D is being built A new style of jeans ...in the USA The journey to the county is very A interest B interests C interesting D interested We should turn... the lights before going to bed A on B up C off D for Vietnamese people are very ...and hospitable A friendly B friend C friendliness D friends