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.
Mozilla has dumped Google in favor of Yahoo as Firefox's default search engine in the US. If you've been using and enjoying Google search, the previous default, in Firefox then you'll need to dig into settings to change it back.o get rid of Yahoo search, open Firefox's Preferences and click on the Search tab. (You can also head directly to the search tab in Preferences by typing a letter in Firefox's search bar to call up the search window before clicking Change Search Settings at the bottom of said window.).