帮我把下面的句子改成单数或负数形式lt's a blue eraser.this is a dictionary.that's my family photo.this is a photo of my family.ls that a box?yes,it ishe is a boy.she isn't a chiese girl.are those apples?they aren't english diciionaries.these are my watches they are good girls.好的50分

lt's a blue eraser.- They're blue erasers.
this is a dictionary.- These are dictionaries.
that's my family photo.- Those are my/ our family photos.
this is a photo of my family.- These are photos of my/ our family.
ls that a box?yes,it is - Are those boxes Yes,they are.
he is a boy.- They are boys.
she isn't a chiese girl.- They aren't Chinese girls.
are those apples?- Is that an apple
they aren't english diciionaries.- It isn't an English dictionary.
these are my watches .- This is my watch.
they are good girls- She is a good girl.
不明白的再问哟,请及时采纳,多谢!