—Good idea. We should always ________ mother's love for us.
(Ⅰ)求椭圆C的方程;
(Ⅱ)过点(0,t)作圆O的一条切线交椭圆C于M,N两点,求△OMN的面积的最大值.
观察下面的算式:
5×9=45
55×99=5445
555×999=554445
5555×9999=55544445
则555555×999999=( )