At the Delaware National Guard facility named for his late son, a somber President Biden on Friday urged veterans to take advantage of new health care opportunities under legislation he signed in August.  The law, known as the PACT Act, helps veterans get screened for exposure to toxins. Those include Agent Orange, which was used for deforestation during the Vietnam War, and burn pits, where trash was destroyed on military bases in Iraq and Afghanistan.  TOPSHOT – US President Joe Biden speaks with Ray Firmani, a 101-year-old World War II veteran, during a town hall with veterans and veteran survivors in New Castle, Delaware, on December 16, 2022. JIM WATSON/AFP…