mongodb查询数组

Question

您好我有以下数据库em mongodb，我需要一个查询来获取数组的单个对象，比如数字为18的对象卡，我所做的所有查询都返回整个数组而不仅仅是我想要的对象，我怎么能这样做？

{"Cards":
              [
                        {"Card":{"_id":{"$oid":"5a46626e150ed3f847f01bac"},"Number":1,"Pag":1}},
                        {"Card":{"_id":{"$oid":"5a466d96150ed3f847f01bad"},"Number":18,"Pag":6}},
                        {"Card":{"_id":{"$oid":"5a466de6150ed3f847f01bae"},"Number":35,"Pag":8}}
              ]
        }