commemorative activities; 纪念活动
observe International Children's Day; 纪念国际儿童节
keep sth. as a souvenir; 留个纪念
My friend gave me his picture as a keepsake before going away. 我的朋友在离别前给我一张照片留作纪念。
牛津高阶第八版
美国韦氏词典
Dictionary.com
Free Dictionary
维基百科 (自由的百科全书)