高压氧对哪项耳聋无辅助治疗作用()。
A.老年性聋
B.药物性聋
C.突发性聋
D.创伤性聋
E.噪音性聋
参考答案:A
宇宙飞船以周期为T绕地球做圆周运动时,由于地球遮挡阳光,会经历“日全食”过程,如图所示.已知地球的半径为R,地球质量为M,引力常量为G,地球自转周期为T0.太阳光可看作平行光,宇航员在A点测出的张角为α,则( )
A.飞船绕地球运动的线速度为2πRTcosα2
B.一天内飞船经历“日全食”的次数为TT0
C.飞船每次“日全食”过程的时间为αT02π
D.飞船周期为T=2πRsinα2RGMsinα2
(), Charles Darwin did much to disprove common theories about biological evolution.
A. He was a highly respected naturalist
B. A naturalist was highly respected
C. A highly respected naturalist
D. Although a highly respected naturalist