After Feng Lei ran out, other students showed the same reaction as Feng Lei. They either had stomachache, pale face or ran to the bathroom with their stomachs in their arms.

Some students ran to the bathroom four or five times in half an hour, and at last the whole person seemed to be falling out.

A third of the dozens of students in Xiaoyang's class had similar reactions.

Actually, this is not only the case in Xiaoyang's class, but also in many classes of Mingde Middle School from Grade One to Grade Three.

When Xiao Yang saw everyone's reaction, four words suddenly appeared in his mind: food poisoning.

Because...