they are pens改为单数句

they are pens改为单数句 Are those pens改为单数句 They are pens(改为否定句） they are pens改为复数句 they are orange sweaters 改为单数句 They are American teachers(改为单数句) Are they women doctors? 改为单数句 They are my friends.改为单数句 They are old jeeps. (改为单数句) 把They are apples.改为单数句 Are they students?（改为单数句） They are English jeeps.改为单数句