in the playground，on the playground 区别 【解答】in the playground与on the playground 完全互相替换，意义相同.on the playground最早出现在英式英语中，in the playground出现在美式英语中.下面辞典中出现例子：用in的例证：1.He bullies all other little boys in the playground.他在运动场上称王称霸，欺负其他小男孩.见商务印书馆的《朗文当代高级英语辞典》bully词条2.He was bashed up in the playground by some older boys.有几个年龄较大的男孩子在操场上对他动武.见商务印书馆的《牛津高阶英汉双解词典》(第四版)bash词条3.children skipping in the playground 在操场中跳绳的儿童，见商务印书馆的《牛津高阶英汉双解词典》(第四版)skip词条4.The children were out in the playground letting off steam.那些孩子在操场上玩，宣泄过剩的精力.见商务印书馆的《牛津高阶英汉双解词典》(第四版)steam词条5.The children were running about in the playground.孩子们在运动场上跑来跑去.见上海外教社的《朗文多功能分类词典》6.There were children fighting in the playground.见《剑桥高级英语词典》(Cambridge Advanced Learner’s Dictionary)的fight词条用on的例证：The children ran out and 。
男童34码鞋内长是多少 按照中国码与欧洲码换算公式：中国码=(欧洲码+10）*5；即中国码=（34+10）*5中国码=220MM，所以内长为22公分
决定智商的基因全部来自X染色体吗？ 据说判断一个男生是否聪明，看他妈妈就知道了。原因是男生的性染色体是XY，X来自母亲，Y来自父亲。女生的…
