A、Eating raw meat. B、Eating processed meat. C、Drinking alcohol. D、Smoking heavily. B新闻开头提到，在周一，世界卫生组织专家表示，食用加工肉类会致癌。

(5)Eating processed meat can cause cancer, World Health Organization experts said Monday.
    Processed meat is meat that has been preserved by curing, salting, smoking, drying or canning.(6)Experts from the WHO’s International Agency for Research on Cancer(IARC)in Lyon, France, studied 800 cases. IARC researchers linked processed meat, such as hot dogs and ham, to bowel cancer, as well as pancreatic cancer and prostate cancer.(7)The IARC has included processed meat in its group 1 list, for which there is "sufficient evidence" of links to cancer. Tobacco, asbestos, and diesel fumes are also on the group 1 list. WHO experts also called red meat, including beef, lamb and pork, "probably" carcinogenic to humans. Dr. Kurt Straif is with the IARC. He said in a statement that the risk of cancer increases with the amount of meat a person eats. A person who consumes 50 grams of processed meat per day—about two pieces of bacon—increases his or her risk of bowel cancer by 18 percent.
5. What can cause cancer according to WHO experts?
6. What did IARC researchers conclude after studying cases?
7. Why has IARC listed processed meat on the top?