非洲某草原生态系统有如图所示的食物网，请据图回答：

（1）这个食物网包括____ 条食物链．

（2）图中属于第三营养级的生物有____，狮子和野狗的关系是____ 

（3）该生态系统除包括图示各成分外，还包括____和____ ．流入该草原生态系统的总能量为____．生态系统输出的能量形式是____

（4）这块草原的生产者固定太阳能为300万千焦/年．按10%能量传递效率计算，设一种生物被下一个营养级各种生物平均摄食，则狮群获得的能量正好维持其种群的生存，此时狮群获得的能量是____ 万千焦/年．

14－3＋5=____

8＋2＋7=____

15－10＋9=____

4＋5＋6=____

阅读下面短文，然后从所给的四个选项中选出一个最佳答案。

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