在证券交易活动中，涉及公司的经营、财务或者对该公司证券的市场价格有重大影响的尚未公开的信息，为内幕信息。（）
参考答案：对
When Tommy’s mother hides his favorite toy under a blanket, he acts as though it no longer exists and makes no attempt to retrieve it. Tommy is clearly in Piaget’s stage:()
A．Sensorimotor
B．Preoperational
C．Formal operational
D．Concrete operational
（）不是密封填料环的作用。
A.冷却轴
B.保护轴
C.润滑轴
D.进行水封
