Possible Clues:

• Class expert possibly needs single to return in hired vehicle on street
• Charge about to subdue old film, one analysing the class system?
• She classifies toxin atoms idiosyncratically
• Biologist has burden and motion's tricky
• Biologist's duty over, with nothing omitted, reportedly
• Classifier of organisms
• Person dealing with the science or practice of plant or animal classification
• He has classified information in his study