<image>(1) A quadrilateral does not have stability. To make a quadrilateral wooden frame stable, at least ____ additional wooden strips are needed.
(2) A pentagon does not have stability. To make a pentagonal wooden frame stable, at least ____ additional wooden strips are needed.
(3) A hexagon does not have stability. To make a hexagonal wooden frame stable, at least ____ additional wooden strips are needed.
(4) An n-sided polygon (n≥4) does not have stability. To make an n-sided polygon wooden frame stable, at least ____ additional wooden strips are needed.