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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def normal_curve_single_list(obj, param_list, normalize):
 """ Evaluates the curve normal vectors at the given list of parameter values. :param obj: input curve :type obj: abstract.Curve :param param_list: parameter list :type param_list: list or tuple :param normalize: if True, the returned vector is converted to a unit vector :type normalize: bool :return: a list containing "point" and "vector" pairs :rtype: tuple """

    ret_vector = []
    for param in param_list:
        temp = normal_curve_single(obj, param, normalize)
        ret_vector.append(temp)
    return tuple(ret_vector)