【单选题】Why does he feel that way?
A.
He has too much to do.
C.
He is getting married.
【单选题】–Where is Lily? --She Chengdu. She there for two days.
【简答题】A、B、C、D均是短周期元素,A和B同周期, B和C同族,A元素族序数是周期数的三倍,B原子最外层电子数是内层电子数的二倍,B与A能生成化合物BA 2 ,C与A生成化合物CA 2 , A的阴离子与D的阳离子电子层结构相同,都与氖原子的电子层结构相同,D 的单质与A 的单质在不同条件下反应,可生成D 2 A或D 2 A 2 。请回答 (1)写出元素符号A: ,B: ,C: 。 (2)D 2 A的电子...
【单选题】Why does he feel that way?
A.
He has too much to do.
C.
He is getting married.
【单选题】对齿轮传动的凸轮轴传动机构,下列齿轮的磨损对定时的影响最大的是()。
【简答题】阅读下面材料,在空白处填入适当的内容(1个单词)或括号内单词的正确形式。 Chengdu has dozens of new millionaires,Asia’s biggest building, and fancy new hotels. But for tourists like me, pandasare its top____61_(attract). So it was a grea...
【简答题】Teahouses in Chengdu There is a saying, “China has the best teahouses in the world and Chengdu has the best teahouses in China.”Chengdu has not only many teahouses but also the special ways of serving...
【单选题】由短周期元素和长周期元素共同组成的族可能是
【简答题】There is a saying, “China has the best teahouses in the world and Chengdu has the best teahouses in China.”Chengdu has not only many teahouses but also the special ways of serving and drinking tea. As...