GRE Text Completion: Kaplan-GRE填空Kaplan - 45EEE0J2PR6RTZFF_

After naturally occurring smallpox was eradicated, the World Health Organization chose to ____________ the remaining samples of the virus in hopes that they might be later used in developing the means to combat other viruses. A. eliminate B. duplicate C. preserve D. retain E. extirpate F. cultivate