A. architecture B. risk C. responsible D. harmful A. middle B. superstructure C. regularity D. display A. news B. gas C. appendix D. at the same time A. try out for B. separate C. rough D. aid A. power B. blame C. answer D. suit A. punish B. emission C. dividend D. precious A. gun B. drive away C. soil D. station A. soda B. fortnight C. dig D. historian A. Seoul B. go into hiding C. clean up D. pollute A. repeat B. winter C. govern D. difference