Over the last 30 years man-made CFCs have been the main cause of stratospheric ozone depletion. CFCs however, are not the only ozone-depleting chemicals. Other ODCs include the methylhalides, carbon tetrachloride (CCl4), carbon tetrafluoride (CF4), and the halons which contain bromine instead of chlorine.
Part of the Internet applications glossary: Yahoo! is an Internet portal that incorporates a search engine and a directory of World Wide Web sites organized in a hierarchy of topic categories.
Some people are brand loyal. They like Microsoft so they stick with the Bing search engine. They use yahoo mail so they search on Yahoo search engine. Often they accept the Bing default on the Internet Explorer browser. Some like the Bing browser interface - it looks pretty nice, actually.