{
  "id": "S050",
  "type": "单选题",
  "type_code": "single",
  "stem": "若直线回归方程y=a+bx中的回归系数b为负数，则说明（ ）。",
  "stem_text": "若直线回归方程y=a+bx中的回归系数b为负数，则说明（ ）。",
  "options": [
    {
      "key": "A",
      "text": "r为0"
    },
    {
      "key": "B",
      "text": "r为负数"
    },
    {
      "key": "C",
      "text": "r为正数"
    },
    {
      "key": "D",
      "text": "r为任意数"
    }
  ],
  "options_text": [
    {
      "key": "A",
      "text": "r为0"
    },
    {
      "key": "B",
      "text": "r为负数"
    },
    {
      "key": "C",
      "text": "r为正数"
    },
    {
      "key": "D",
      "text": "r为任意数"
    }
  ],
  "answer_keys": [
    "B"
  ],
  "answer_display": "B",
  "answer_texts": [
    "r为负数"
  ],
  "sources": [
    {
      "edition": "第12届",
      "edition_num": 12,
      "no": 50,
      "uid": "12-050",
      "file": "第12届本科模拟题（10.19）.xlsx"
    }
  ],
  "source_display": "第12届 第50题",
  "source_count": 1,
  "images": [],
  "warnings": [],
  "conflict": null,
  "url": "/q/S050.html"
}