A:By studying with a group.
B:By asking his teacher questions.
C:By remembering all the words.
“铁人”王进喜克服重重困难打出大庆第一口油井,焦裕禄为改变兰考面貌献出生命,邓稼先完成我国第一颗原子弹的理论设计方案,他们(如下图)的事迹出现在( )
( I)证明:AE⊥CD
( II)在棱ED上是否存在点M,使得直线AM与平面EFBD所成角的正弦值为 63 ?若存在,确定点M的位置;若不存在,请说明理由.
宋太祖在位期间,为加强中央集权,采取了哪些措施?