Flask second parameter returns null

Question

when I try to return the second argument background for my Flask application, I get a null value, but it works fine for original

> curl http://127.0.0.1:5000?original="sdsd" & background="/szzzzzz" 

@app.route('/',methods=['GET'])
def API():
    if request.method == 'GET':
        original = request.args.get('original')
        background = request.args.get('background')
        result =  background
        return jsonify(result)