about question set

Could you tell me what wrong with my dataset.
When I upload my datasets, I wiil got "The dataset couldn't be loaded".
I think I've followed the rules in https://github.com/dice-group/gerbil/wiki/Question-Answering.
My datasets seems like this:
{"questions": [
{"query": {"sparql": "PREFIX res: \nPREFIX prop: \nSELECT ?date\nWHERE \n{\n res:LucasArts prop:foundation ?date .\n}"}, "question": [{"string": "When was Lucas Arts founded?", "language": "en"}], "id": "41_1_dbpedia-train-CDATA", "answers": [{"results": {"bindings": [{"type": "literal", "value": "May 1982"}]}}]},
{"query": {"sparql": "PREFIX dbp: \nASK \nWHERE { \n dbp:mother ?x . \n dbp:mother ?y . \n FILTER (?x = ?y) \n}"}, "question": [{"string": "Do Prince Harry and Prince William have the same mother?", "language": "en"}], "id": "123_qald-4_multilingual_train_withanswers", "answers": [{"boolean": true}]}
]}