单选题 These varied racial groups have learned to live together in peace and ______ , setting an example well worth following.

【正确答案】 A

【答案解析】[解析] [A]harmony意为“和谐，和睦”，in harmony构成介词词组，故为答案。而[B]grace意为“优美，雅致”；[C]rhythm意为“节奏，韵律”；[D]relief意为“减轻，解除”。