บทคัดย่อ, เศษส่วน, เส้น, ดอกไม้, ใบไม้, อาสาสมัคร, แผ่ออกไป
Public Domain
ภาพถ่ายปลอดค่าลิขสิทธิ์ที่เกี่ยวข้อง
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