直线xsinα+y+2=0的倾斜角的取值范围是( ).
A:0,π)
B:0,π4∪3π4,π)
C:0,π4
D:0,π4∪π2,π
下列有关化学实验的说法正确的是( )
直线L圆x2+(y﹣2)2=2相切,且直线L在两坐标轴上的截距相等,则这样的直线L的条数为( )
—Dad, I'll be in the final singing competition tomorrow.
—Be careful not to get a sore throat and your voice.