What is the function of the large, sheetlike pectoralis muscles of a bird it moves the tail to form a rutter system it anchors the feet when the bird perches it provides the wing upstroke it provides the wing's downstroke?

It is the doctrine that the us had the right and duty to expand throughout north america. it just means they believed they had the right to expand westward and they did! they stated with the 13 colonies and then they kept moving gaining different territories throughout the years

Answer decreased soil salinity;