If you often feel uncomfortable, you ___ lie down and have a rest.
A：must
B：would
C：might
D：should
鹅的步调从容，大模____大样，颇像京剧里的净角____出场。
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____．
