请以json格式回答：东京和北京一年四季的温度差异大致是怎样的？
user
```json
{
  "cities": [
    {
      "name": "Tokyo",
      "seasons": [
        {
          "season": "Spring",
          "temperature_range": "10°C to 20°C"
        },
        {
          "season": "Summer",
          "temperature_range": "25°C to 35°C"
        },
        {
          "season": "Autumn",
          "temperature_range": "15°C to 25°C"
        },
        {
          "season": "Winter",
          "temperature_range": "0°C to 10°C"
        }
      ]
    },
    {
      "name": "Beijing",
      "seasons": [
        {
          "season": "Spring",
          "temperature_range": "10°C to 25°C"
        },
        {
          "season": "Summer",
          "temperature_range": "25°C to 38°C"
        },
        {
          "season": "Autumn",
          "temperature_range": "5°C to 20°C"
        },
        {
          "season": "Winter",
          "temperature_range": "-10°C to 5°C"
        }
      ]
    }
  ],
  "comparison": "Tokyo generally has milder winters and cooler summers compared to Beijing, which experiences more extreme temperature variations between seasons."
}
```
assistant