A:染色体的非着丝点区域
B:细胞板
C:构成纺锤体的星射线
D:染色体的着丝点
求以椭圆9x2+5y2=45的焦点为焦点,且经过点M(2,)的椭圆的标准方程____.
What really________is whether you have good computing skills,not how long you have worked here.