Which of the following must happen first if natural selection is going to take place? 1. variation in organisms 2. selective advantage of one trait over another 3. reproduction 4. time 5. generic mutation

20 points and brainlist 1. london has suffered from terrible air pollution for at least seven centuries. why is the city so prone to its famous “london fog? ” what did london do to get rid of its air pollution? 2. why does air pollution cause problems in developing nations more than in developed ones?