单选题 Color-blind people often find it difficult to ______ between blue and green.
A. distinguish B. compare C. separate D. contrast

【正确答案】 A

【答案解析】distinguish“辨别，分辨”，distinguish between或distinguish...from...；compare“比较”，compare with (to); separate“分(隔)开”，separate...from...；contrast“对比；对照”，及物动词或contrast...with...。