Some experts believed, and _______ did we, kids who reach adolescence still need at least nine hours' sleeping.
A：that
B：as
C：neither
D：so
据科学家分析，海洋生物比陆地生物进化的速度要缓慢，按达尔文自然选择学说，分析其原因是( )
已知2sinαtanα=3，且0＜α＜π．求α的值；
