— Is there a library in Gaochun?
— Yes, a new library _______ and is now open to the public.
A:will be built
B:was built
C:has been built
D:is built
如图,在△ABC中,∠CAB=∠CBA=30°,AC、BC边上的高分别为BD、AE,垂足分别是D、E,则以A、B为焦点且过D、E的椭圆与双曲线的离心率分别为e1,e2,则1e1+1e2的值为 ( )
传感器的输出量通常为( )
____