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I had a summer camp with my classmates for a week last year.
Early in the morning, we gathered(聚集) at the bus station. After saying goodbye to our parents, we got on the buses. It took us more than two hours to arrive at the campground.
We got off the buses happily. Laughing and shouting, we jumped and ran all over the place. It was the first time for us to be away from the parents. Some of us started to feel homesick(想家). However, when the night party and dances began, we felt excited again.
The next day, everybody rushed to the boating class, hoping to be at the head of the others. At first, my friends and I worked hard, but the boat wouldn't listen to us and kept going round and round. Then the teacher taught us how to work together. After many tries, we did much better.
Swimming class was my favourite. It was about the hottest time of a day and the best time to stay in the cool water. The swimming teacher was a funny man, and during the class he often made us laugh happily. During the week I learned a lot of new things and made many new friends. I also learned how to take care of myself.
有两个不等实根，则k的取值范围是（ ）