选择合适的词完成句子
（some, any, is, are,
1.---_____there a ruler in the pencil-box?
---Yes,there____.
2.There ____an elephant in the zoo.
3.There are't ____doctorsin the room.
4.--____ there ____books under the desk?
--Yes, there ____.
5.There are ____ trees in the park.