cindy southworth and ashley parker, we thank you both. >> thank you. >> thank you so much. >> brown: again, the major developments of the day: pope benedict the 16th made a final appearance and then left the vatican-- the first pontiff in 600 years to resign. and u.s. army private bradley manning entered guilty pleas to some of the charges against him in a huge leak of classified material to wikileaks. >> woodruff: online, we take a look inside a virginia gun show. hari sreenivasan has the story. >> sreenivasan: amid the national debate on gun control, hear what gun enthusiasts had to say at a recent exhibit just outside the nation's capital. our multimedia project is on our homepage. and 60 years ago today, two men discovered the secret of life-- d.n.a. learn more about james watson and francis crick on our health page. all that and more is on our website newshour.pbs.org. jeff? >> brown: and that's the "newshour" for tonight. i'm jeffrey brown. >> woodruff: and i'm judy woodruff. we'll see you online and again here tomorrow evening with mark shields and david brooks, among others.