The colorless solution of the following substances can be identified without other reagents：
<1> KOH , Na2SO4 , AlCl3
<2>NaHCO3 , Ba(OH)2 , H2SO4
<3>HCl , NaAlO2 , NaHSO4
<4>Ca(OH)2 , Na2CO3 , BaCl2

A. <1><2>
B.<2><3>
C.<1><3><4>
D <1><2><4>

Help, Lots thanks 谢谢帮助，朋友们

thats a little if u want the answer just look it up on google thats what i do haha : )

in the analysis of systems that involve fluid flow, we frequently encounter the combination of properties u and pv.

explanation:

two years ago, when picking flowers in the mountains back of yosemite valley, i found a book. it was blotted and storm-beaten; all of its outer pages were mealy and crumbly. the paper seemed to dissolve like the snow beneath which it had been buried, however; many of the inner pages were well preserved. and although all were more or less stained and torn, whole chapters were easily readable. this is the condition of the great open book of yosemite glaciers today; its granite pages have been torn and blurred by the same storms that wasted the castaway book.

two years ago, when picking flowers in the mountains back of yosemite valley; i found a book. it was blotted and storm-beaten, all of its outer pages were mealy and crumbly. the paper seemed to dissolve like the snow beneath which it had been buried, however, many of the inner pages were well preserved. and although all were more or less stained and torn; whole chapters were easily readable. this is the condition of the great open book of yosemite glaciers today, its granite pages have been torn and blurred by the same storms that wasted the castaway book.