- How many birds are there? ( )
- ________
A:Yellow.
B:Ten.
C:Yes, I have.
— _____ Dasan is from Canada, he can speak Chinese very well. — I know he studies Chinese hard.
如图1,在正方形ABCD中,延长BC至M,使BM=DN,连接MN交BD延长线于点E.
下列有关六方最密堆积与面心立方最密堆积的说法中正确的是( )
已知动点P(x,y)在椭圆x225+y216=1上,若A点坐标为(3,0),AM→=1,且PM→·AM→=0,则PM→的最小值是( )