已知半径为1的球面上有A、B、C三个点,且它们之间的球面距离都为,则球心O到平面ABC的距离为( )A. B. C. D. 答案:答案:B解析:如图,设球心为O,则OA、OB、OC的长均为半径1,且两两成的角,则四点O、A、B、C构成正四面体的四个顶点,如图,OH=.
The villagers are ________ the factory.They keep complaining about the noise.
[ ]
A.
pleased with
B.
fed up with
C.
surprised at
D.
worried about