The common middle-school schedule that involves students changing rooms, teachers, and classmates every 40 minutes .

explanation:

allergens: overstimulate the nerve system

neurotics: attack nerve cells

mutagens: damage or otherwise alter dna sequence

generators: cause defects during growth and development  

carcinogens: cause unchecked cell growth

i hope you get the idea according to me these are the effects that happened.

citizens were able to charge more for their goods and services

answer; evidence; reverseremand;

answer; the three types of research;