Are these nice pictures 改为单数句

Are these nice pictures 改为单数句 改为感叹句These pictures are very nice. These girls are nice改为否定句 These are his brothers 改为单数句 These are yellow purses.(改为单数句) These are dishes 改为单数句 These are my pencils改为单数句 These are his watch.改为单数句 are these old coats 改为单数句 These are boxes. (改为单数句） These are apple trees(改为单数句) Are these orange quilts?改为单数句