My best friend is one of my classmates. Her name is Mary. Every day, we go to school together and go back home together. We often help each other and learn from each other in study. We have the same hobby-collecting stamps. She has many
在课外活动中,我们要研究一种凹四边形﹣﹣燕尾四边形的性质.
计算-12ab23的结果是
按要求画图:
①在 的右面画
②在 的左面画
③在 的上面画
④在 的下面画
根据提示补写名句或填写课文原句
据最新科技报道,美国科学家发现了新型的氢粒子H3+,该粒子是( )