His parents are doctors.中的are doctors是什么语

His parents are doctors.中的are doctors是什么语 His parents are doctors.为什么谓语是are doctors 而不是are? My parents are b____ doctors. The_____(twin)parents are doctors parents,both,his,doctors,are 连词成句 (both,all)of her parents are doctors. B____ of my parents are doctors. And Juck's parents are （ ）doctors. My parents are doctor 还是My parents are both doctors He can ride bike .His parents' job are doctors .这两句话有什么错误? ___of her parents are teachers.They are doctors. 用are both或both are填空:My parents ( ) doctors.