These are ours改为单复数形式

These are ours改为单复数形式 are these desks?单复数形式 Are these your friends.改为单复数 These books are ours.(改为一般疑问 Whose teachers are these They are ours改成单数形式 Is this a bus?(改为复数形式） Those are erasers.(改为单复数形式） These boxes are ours氦为单数形式 These boxes are ours.(氦为单数形式) this your friend?(改为复数形式) 问题二Are these your books?(改为单数形式) ' These are my keys.改为否定句,改为单复数转换改为一般疑问句或提问,肯定句做回答. 改错：These are ours books These books are yours.(用ours改为选择疑问句）___ these books yours __