Which may cause incapacity of pilots? （ ）

It is difficult to apply work-family balance laws in America because of the incapacity of the Democrats. 未知类型：{'label': 'questionDesc', 'content': '请根据所给材料判断题干是否正确。', 'isMemberControl': 0, 'type': 181} 未知类型：{'label': 'source', 'content': '粉笔英语独家模拟卷 六级 仔细阅读2', 'isMemberControl': 0, 'type': 181}