parse json without explciitely calling the key-name

I have a json-like file with valid json per line that looks like

{"Some_key": {"name": "Tom", "school_code":"5678", "sport": "football", "score":"3.46", "classId": "456"}}

{"Another_one": {"name": "Helen", "school_code":"7657", "sport": ["swimming", "score":"9.8", "classId": "865"}}

{"Yet_another_one_": {"name": "Mikle", "school_code":"7655", "sport": "tennis", "score":"5.7", "classId": "76532"}}

So I need to create dictionary(? not really need the dictionary format but anything that could help me associate the key with value, array of two elements for ex) by extracting these first keys (i.e. "Some_Key", "Another_key" etc), that I don't know in advance, and then associating to them the value of score key inside the dictionary. so something like:

("Some_key":"3.46", "Another_Key":"9.8", "Yet_another_one_"; "5.7")

I don't know the method to extract the content without calling the key-name explicitly, so your ideas are more than welcome !