如图为某区域地质剖面示意图，读图回答问题．

①How many children are there? ____            A. It's forty yuan.

②What are they doing? ____                          B. Playing basketball.

③How much is the basketball? ____               C. Every afternoon.

④How often do they play basketball?____     D. Tired and exhausted.

⑤How do they feel now? ____                        E. There are nine.

⑥Where do they play basketball? ____           F. In the gym.

“综合与实践”学习活动准备制作一组三角形，记这些三角形的三边分别为a，b，c，并且这些三角形三边的长度为大于1且小于5的整数个单位长度．