The United States today is the______largest country in size in the world.A．secondB．thirdC．

The United States is composed of fifty states, two of ______ are separated from the others

______ is the longest river in the United States.A．The Waikato RiverB．The Mackenzie RiverC

In the United States, the head of the executive branch is______.A．the CongressB．the Suprem

In the United States, the Senate is presided over by______of the United States.A．the presi

In the United States, ______is called the "Father of Waters".A．the Mississippi RiverB．the

The national bird of the United States is______.A．sparrowB．swallowC．eagleD．swan