【单选题】关于元素周期表,下列表述中正确的是( )。
【判断题】元素周期表中有8个主族,8个副族,共16族。
【简答题】元素周期表有 个周期, 个主族, 个副族。
【单选题】Although people spend less time on their jobs, they still feel they do not have enough leisure time because of the following except ______.
A.
spending some time with their children
B.
doing physical exercises
C.
spending some time on learning
D.
fulfilling family and social obligations
【单选题】The survery shows that if people cannot afford house, they will feel less content about ___life.
【单选题】People would feel less stressed.
【单选题】“保险合同履行的结果建立在事件可能发生,也可能不发生的基础上。”这是指保险合同是一种( )
【单选题】Although people spend less time on their jobs, they still feel they do not have enough leisure time because of the following except ______.
A.
fulfilling family and social obligations
B.
spending some time with their children
C.
spending some time on learning
D.
doing physical exercises
【单选题】People who exercise _______________ are less likely to feel stress.
【简答题】元素周期表知识 元素周期表中有 ( )个周期, ( )主族 周期数= ( ) 主族数= ( )