The luxury carmaker Mercedes-Benz will shift its focus entirely to electric vehicles in 2025 and sell nothing but electric cars by 2030. While it said the transition depends on market conditions, Mercedes thus joined a growing list of automakers who are abandoning internal combustion engines. They have little choice. The European Union will effectively ban new cars with internal combustion engines in 2035, while Britain, Norway and other countries also have set expiration dates. Coping with pressure from Tesla, which is building a factory in Berlin, Mercedes plans to unveil a model next year that will go 600 miles on a charge -- about 50% further than Tesla's longest-range car.