Taiwan's Mirage 2000 fighter squadron takes off from Hsinchu, the island's semiconductor heartland, as Chinese warplanes and and warships conduct exercises around the Taiwan Strait on the second day of a huge military drill. Beijing says the exercises are a "necessary" response to Nancy Pelosi's visit to the self-ruled island earlier this week. Taiwan accounts for more than 90 percent of the world's most advanced semiconductor production, much of it centered in Hsinchu Science Park. IMAGES AND SOUNDBITES