A what introduces a bill the floor of the House pf Representatives

A hopper, a special box

Explanation:

In the U.S. House of Representatives, a bill is introduced when it is placed in the hopper—a special box on the side of the clerk's desk. ... A reading clerk then reads the bill to all the Representatives, and the Speaker of the House sends the bill to one of the House standing committees.

the answer to your question is a. the salt plains

in 1811, he led an expedition, known as the george c. sibley expedition, to improve relations with the pawnee and kansa tribes, and also to locate the rumored jefferson's salt mountain