在直角坐标系xOy中，以原点O为极点，以x轴正半轴为极轴，曲线C的极坐标方程为ρ=$\frac{\sin \theta }{{\cos }^2\theta }$．

将曲线C的极坐标方程化为直角坐标方程

（Ⅰ）求椭圆的方程；

（Ⅱ）过点 $P\left(0，\frac{5}{3}\right)$ 的直线l与椭圆交于两个不同的点M，N，求线段MN的垂直平分线在y轴上截距的取值范围．

我国人民民主专政的本质是（   ）

根据短文理解选择答案。

    In many English homes people eat four meals a day. They have breakfast at any time from seven to nine in the morning. They eat porridge(粥), eggs or bread and drink tea or coffee for breakfast. Lunch comes at one o’clock. Afternoon tea is from four to five and dinner is about half past seven. First they have soup, and then they have meat or fish with vegetables. After that they eat some other things, like bananas, apples or oranges. But not all English people eat like that. That is to say, most Englishmen have breakfast, lunch, afternoon tea and dinner in a day.