Don’t worry. There is wrong with the TV set. It’s only because of power cut.
A:something
B:nothing
C:anything
D:everything
—How many people were invited to the meeting?
—About six ________.
(Ⅰ)求证:BD∥平面FGH;
(Ⅱ)若CF⊥平面ABC,AB⊥BC,CF=DE,∠BAC=45°,求平面FGH与平面ACFD所成的角(锐角)的大小.
设圆的面积为S,半径为R, 那么下列说法正确的是( )
中国读书人历来“耻于言商,耻于言利”,而清末“状元实业家”张謇却放弃仕途,投身于近代工商业。这里反映出的观念意识是( )