A. introduce B. what's C. observation D. ant A. Nile B. above all C. rapid D. threaten A. cure B. wait and see C. in rags D. extinction A. go boating B. stalactite C. exploit D. honour A. wait a moment B. sentence C. correctly D. erase A. member state B. patronage C. patient D. sometime A. velvet B. first-ever C. saw D. crayon A. discovery B. cheetah C. plan D. wood A. century B. shove C. convoy D. great auk A. piece B. lab C. orchestra D. meanwhile