答案与解析:
每隔3页放进一片树叶,15页共有如图所示,
□□□○□□□○□□□○□□□○□□□
需要放进4片叶子。
2025-12-09
2025-10-15
2025-09-16
2025-08-21
2025-07-25
2025-07-21
2025-07-16
2025-07-15