题干
——Though radio and television are ____ popular in the world today, I think the TV is ____ useful.
——Of course, on TV we can see and hear what is going on home and abroad.
A：more, less
B：very, more
C：more, more
D：very, less
答案(点此获取答案解析）
B
， 
， 
是此椭圆上的一点，且 
， 
，则该椭圆的方程是( )