单选题 下面代码实现了在数据集中留出部分验证数据(validation_images,validation_labels)的操作. validation_images = train_images[:10000] train_images = train_images[10000:] validation_labels = train_labels[:10000] train_labels = train_labels[10000:] 请问验证数据集在原数据集中的索引范围是