Five major Arthropod classes
Arachnida. mites, ticks, spiders, scorpions.
Chilopoda. Centipedes.
Crustacea. (crabs, lobsters, shrimp.
Diplopoda. Millipedes.
Hexapoda. Insects.
so your answer will be mollusks
Answer:
Control group
Explanation:
A control group is<em> a group of individuals in an experiment where the independent variable being tested (the exposition to cigarette smoke in this case) can't influence the results.</em> This control group will be then compared to the experimental group (exposed to the smoke) to see the effect of the variable evaluated.
I hope you find this information usefula nd interesting! Good luck!