Give my sister back

"Whats the matter? Xiao Jiao asked as she peered at Mo Qiang's forehead while the latter was gazing at the pool of acid in front of them. She clutched the front bangs of Mo Qiang and looked down waiting for Mo Qiang to answer her question. 

Mo Qiang peered at the pool of acid and gasped, "There are no human bones in there! Neither molten nor residue!" Mo Qiang said to Xiao Jiao whose eyes widened. There were no human bones' residue? Then where did the humans who were kidnapped and thrown to the pit of the snake go?

Xiao Jiao was confused but the one who was even more confused was Mo Qiang. Don't tell her, that this snake's digestion was so, so good that it ate everything clean and even the assessing system could not detect it!