It was an act passed by Nixon to prevent Russia, China, North and South Korea from entering into Germany during World War 2
Germany sent Mexico a document trying to get them to declare war on the USA and thereby prevent USA from entering the war on the side of the Allies. The British intercepted the document and after they showed it to the Americans, the USA declared war on Germany, entering WWI.
because the slaves can make plans to rebel against their owners, and try and get free.
to prevent french colonism
What? They did not prevent a civil war, they fought one .
Monopoly and Oligopoly are two barriers that prevent firms from entering the marketplace.
Shutting it.
Epiglottis
no
Phospholipids in the cell membrane prevent water from entering a cell.
to close windows and doors
It is to prevent dust from wood from entering your eye.
Phospholipids
To prevent food entering the trachea
To prevent food entering the trachea
The Goalie
Mediterranean Sea