题目

Last week I went to Corsica with my friends on vacation. It was my first visit to the island! We took the ship from Toulon, France, to the city Ajaccio. Although Toulon and Ajaccio seemed quite close, it took us eight hours. We chatted and played card games to kill time.When we got there, I got a surprise because of the weather. It was already October! But we just needed to wear T-shirts and shorts. We went to the beach to enjoy the sunshine and some of my friends even went swimming in the sea. The Corsican scenery (风景) was so beautiful. We had a picnic, went for a long walk along the coas．设不等式组表示的平面区域为，不等式（，为常数）表示的平面区域为，为平面上任意一点，：点在区域内，：点在区域内，若是的充分不必要条件，则的取值范围是A．B．C．D．