【单选题】某元素位于元素周期表中第3周期,ⅡA族,则该元素的核电荷数为( )
【简答题】小明探究水沸腾时温度变化的特点,实验装置如图甲所示。 ( 1 )加热一定时间后,温度计的示数如图甲中所示,此时水的温度为 ____________度 。 ( 2 )你看出图甲所示实验中的不当之处了吗?请写出你的改正措施 ____________ ,这样做的目的是 ____________ 。 ( 3 )改正错误后,继续实验,记录的数据如表,分析表中数据可知, 1水的沸点为 ____________...
【单选题】a discussion between two students about a project they are doing
【简答题】操作查询共有四种类型,分别是删除查询、生成表查询、【 】和更新查询。
【简答题】It’s known to us all that elephants are the biggest animals on land. There are two kinds of elephants: African elephants and Indian elephants. The African elephant has a round head and very big ears. ...
【单选题】目前我国与欧洲正在广泛使用的GSM(全球通)手机属于( )移动通信
【简答题】Section C: I promise you are going to enjoy your stay here in our city. This is a beautiful, quiet city where you can 11 , sit by the beach,enjoy great meals and feel safe. You can walk into town and ...