A:a﹣9>b﹣9
B:3b<3a
C:﹣2a>﹣2b
D:a5 > b5
贵阳到北京便捷的铁路干线是湘黔线和京广线。( )(判断对错)
看图,选词填空。
Dear Bob,
Please come to my twelfth birthday party tomorrow evening. Now let me tell you how to come.
A. left B. science museum C. east D. park E. flat
用湿毛巾擦已经亮的灯泡不会触电,安全。( )
如图,已知梯形ABCO的底边AO在x轴上,BC∥AO,AB⊥AO,过点C的双曲线y=kx交OB于D,且OD:DB=1:2,若△OBC的面积等于n,则k的值( )