Distinguish the letters’ pronunciations. (选出划线部分读音不同的单词)
(_________)1. A. nurse B. north C. fur
(_________)2. A. born B. burn C. turtle
(_________)3. A. dirt B. mirror C. bird
(_________)4. A. hot B. hurt C. job
(_________)5. A. purse B. player C. tiger