学校心理健康教育活动设计中,是单个集体活动组成集体活动,具有主题鲜明、内容丰富的特点,这体现了:()
A、科学性原则
B、系统性原则
C、多样性原则
D、开放性原则
参考答案:B
李慧同学为了测一只正在煲粥的电饭煲的实际电功率,她关闭了家中其他所有家用电器,这时她家标有“3000revs/(kW•h)”字样的电能表的转盘每分钟转过15圈,则这只电饭煲当时的实际电功率为( )
A.15W
B.200W
C.300W
D.3000W
By referring to Sam' s broken bicycle, the author intends to ______.
A.illustrate the ways to repair his bicycle
B.discuss the problems of his bicycle
C.tell us how to solve a problem
D.show us how to analyze a problem