←
Back
🏠
Home
一个书架上共有27本书,从上层拿走1本放入中层,再从上层拿走2本放入下层,这时三层书架上的书同样多,原来上、中、下层书架上各有书多少本?
Loading Player...
📋
Info
💬
AI Explanation
📝
Subtitles
Downloads
⬇️ Download Video (MP4)
Cover URL
Copy