CNN News:美國各地民眾將參加陣亡將士紀(jì)念日活動

That's because certain strains of E.coli when they contaminate food can cause abdominal cramping, serious intestinal problems, fever or kidney failure. And estimated 265,000 Americans get infected from this every year. A dangerous strain of E. coli might have made its way in the beef products sold in nine states. 11 people are thought to have gotten sick from it, ten of them ate at restaurants that received contaminated meat. The U.S. Department of Agriculture says 1.8 million pounds of ground beef have been recalled. An officials says it's currently being removed from store shelves, but some it has already sold. Dr. Sanjay Gupta tells, you what to look out for.

If you have any ground been in your freezer that says 2574B, that's the lot number that's of concern. You want to throw that out. Don't take any chances.

E. coli is a particularly-the strains of it is a particularly nasty player. Just 100 cells can make somebody ill, and if left untouched it will double the number ever 15 to 20 minutes. So, you can get to billions of cells, you know, fairly quickly. And that's why people are really, really-being very cautious about this. Don't take any chances. Even if you don't have this ground beef, even you've thrown it away, it's Memorial Day weekend. If you are grilling, use a thermometer. That could be the best advice I give you all weekend. Use a thermometer, take a look at the numbers there. That's what you're going to be shooting for. I use the thermometer. It helps keep me and my family safe. You should do the same thing.

While grilling out is one thing associated with Memorial Day in the U.S., it's observed next Monday, but the holiday wasn't always called Memorial Day. Back in the late 1860s, it was knows as Decoration Day, recalling when flowers were placed on the graves of those who died in the Civil War. Over the decades and conflicts that followed, it became Memorial Day, a time to honor and remember all U.S. service men and women who died in wartime. Church services, parades, speeches, a wreath laying at the tombs of the Unknowns, these are some of the events that take place every year on the last Monday in May. Symbolically, it's also seen as the beginning of summer in the U.S.

From South to North, here are three of the schools watching us today. It's time for "The Roll Call" starting in the Volunteer state. Oak Ridge High School, great to see you watching in Oak Ridge, Tennessee. It's the home of the wild cats. In the show-me-state, show-me the warriors. We see them at Fox High School in Arnold, Missouri. And the lumberjacks are online, in the land of 10,000 lakes. At Bemidji High School in Bemidji, Minnesota, thank you for watching.

Space travel is expensive. It's dangerous. And it's fascinating. Fewer than 600 people have ever done it.