C139 Investigate the Poisoning

"There must be something we haven't noticed." Bai Changjie carefully thought about every detail.

"Big brother, why don't we interrogate them one by one?" Bai Changrong asked tentatively.

"Second Uncle, there are so many people in the Martial Arts Association. How long do we need to ask them one by one? Besides, if the news of us investigating the poison is spread out, I'm afraid that if we do