根据汉语提示完成句子,每空一词。
1·John's parents(约翰的父母) work in a big hospital.
2·This is _my sister's book_(我妹妹的书).
3·The students ' desks and chairs (学生们的桌椅) are very new.
4·Please open_ your box_ (你的盒子).
5·John's and Sally's mothers (John和Sally的母亲) are American.