阅读理解。 In 2006,I spent 3 glorious weeks in South Africa.It was my first time traveling on the African continent and truly each day was filled with one adventure after another.That was the craziest and the most dangerous experience I have ever had. On the morning of the excursion,I met with my friends for breakfast,with little conversation.I supposed we were nervous about the day ahead of us.The coach then drove us from Cape Town to Dyer Island in Gansbaii. As soon as we got to our destination,we were quickly pushed into a boat.About 2 hours into the boat we spotted our first shark.It was one of the world's deadliest predators(食肉动物)-a Great White shark Our guide told us that we had to get into the water immediately.Without any formal preparation or instruction,we put our thick wet suits on and jumped into the iron cage. There I was in this tiny cage with 3 Great White sharks circling around me.I tried desperately to take pictures with my underwater camera,not letting my hands and feet drift(漂)out of the cage. When I took a breath,life above the water seemed chaotic(混乱的)．But,I would drop back under the water and life would seem to stop existing.And the sharks that always appeared frightening on TV or in photographs actually appeared peaceful in person. After an hour,I decided it was probably time for me to get out once the sharks started to become really aggressive.I waited until the very last second I could,since I knew I would probably never do this again. 1.What is the text mainly about? A. My travel in Africa for the first time. B. The Great White sharks in South Africa. C. A thrilling experience of spotting Great White sharks. D. The way to protect oneself when meeting with sharks. 2. When the author and his or her friends had breakfast,_____ A. they talked briefly about the plan that day B. they discussed the sharks carefully C. they were nervous about the coming event D. the coach arrived to send them to see the sharks 3. On seeing the sharks,the author and his or her friends_____. A. prepared themselves at once before getting into the water B. got known about the sharks from the guide's introduction C. jumped into the sea under the instruction of the coach D. got into the water with the protection of a cage 4. According to the fifth paragraph,the sharks under the water seemed_____. A. aggressive B. chaotic C. quiet D. frightening 5. The author got back into the boat_____. A. when the sharks began attacking others B. after taking enough photographs of the sharks C. when he or she felt too tired to stay under the water D. before he or she might be at risk of being attacked by sharks 6. 用30个词左右概括文章大意 _______________________________________________________ _______________________________________________________ _______________________________________________________