that is his uncle 的复数形式是什么

that is his uncle 的复数形式是什么 Is that his uncle的复数形式 That is his brother的复数形式 is that his key (改为复数形式) that is his sister改为复数形式 uncle的复数形式 his 的复数形式是什么? what is his name?复数形式是什么 Is that man his uncle? that的复数形式是什么 Is that an orange的复数形式是什么? that is a biack knife的复数形式是什么