在△ABC中,sin2A≤sin2B+sin2C﹣sinBsinC,则A的取值范围是( )
A:(0,π6
B:(0,π3
C:π6,π)
D:π3,π)
下列关于纯合子和杂合子的叙述,正确的是
________that the way people spend their Spring Festival has changed a lot in the past ten years.
16.7×2.1-10.8=____