8. The Center for Disease Control reminded citizens traveling overseas during the holidays to be contagious diseases. (A) in contrast to (B) by means of (C) on guard against (D) at odds with

15. Most presidents want to be reelected to a second term, taken seriously by other world leaders, and remembered after they leave office. (A) fondly (B) barely (C) dully (D) vainly II、文法挑錯：其中有一個是錯誤的，請選出錯誤的選項。