A:﹣ 2
B:2
C:﹣ 2 或 2
D:0
— My cousin is good at all his subjects at school, but he never ________.
— What a ________ boy! We should learn from him.
要得到函数y=2sin2x的图像,只需要将函数y=3sin2x-cos2x的图像 ( )
see(过去式)____
已知圆锥的母线长为5,底面半径为3,则圆锥的表面积为( )