曼哈顿语探究

黑皮一点白

1、Our system of Presidential elections favors states,such as Delaware,that by population areover-represented in the Electoral College.这是一个例句，我的问题是这个不是非限定性定语从句吗，怎么可以用that呢
2、An ice sheet covers 80 percent of the surface of Greenland, an area roughly the size of Alaska. 想问问大家 an area roughly the size of Alaska. 做什么成分，读起来怪怪的，两个名词中间加一个副词。