阅读理解

    My family is not very big. There are only three cats. I'm a white cat. My name is Snow White. My husband (丈夫) is a black cat. His name is Captain Black Cat. We have a pretty (漂亮的) daughter. Her name is Lily. She is black and white. She's two years old. We live a happy life.

    Every day we work hard to catch the mice (捉老鼠).  We help people live a happy life in this house.

如图，将矩形ABCD绕点C顺时针旋转90°得到矩形FGCE，点M、N分别是BD、GE的中点，若BC=14，CE=2，则MN的长（   ）

我国最大的淡水湖是 （  ）