209. Knowing the rewards of ______ , NASA astronaut Ellen Ochoa encourages students to study hard if they wish to pursue careers in science and engineering.
A. generosity
B. serendipity
C. diligence
D. individuality
E. merriment
210. The editor did not wish to print an article based on mere ______ ; she therefore ordered the reporter to find convincing ______ .
A. substantiation, data
B. speculation, guesswork
C. conjecture, proof
D. amicability, rationalization
E. explanation, interpretation