Picket
Monopoly and Oligopoly are two barriers that prevent firms from entering the marketplace.
Individuals are required to declare amounts over 10,000 when entering or leaving a country to prevent money laundering and ensure compliance with financial regulations.
Shutting it.
Epiglottis
no
Steel wool is the best mice hole filler to prevent rodents from entering your home.
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