1. There is not some milk in the bottle. / There isn't some milk in the bottle.
2. There are not two chairs and one armchair in the sitting room. / There aren't two chairs and one armchair in the sitting room.
3. There are not three apples and one pear in the box. / There aren't three apples and one pear in the box.
4. There is not some grapefruit juice in the glass. / There isn't some grapefruit juice in the glass.
5. There are not new houses in this street. / There aren't new houses in this street.