下列关于二叉树定价模型的说法，错误的是______。 A．该模型假定在期权到期时股票

根据首字母填空

1. We can eat meals in the d             hall in our school.

2. There is a bank n              to the hospital.

3. In our school,there is a big l             ,we often read book in it.

4. His father bought(买) a d             for her.it can help her study.

5. Ten and forty is            .

6. There is a football match in the g           .

7. This is a 5-star h            .

8. My mother often takes me to the clear p           ;there are many people play in it.

结合水主要性质为：①（）②（）③（）④（）。

假定上题中这两个厂商同意建立一个卡特尔，以使他们的总利润最大化，并同意将增加的总利润在两个厂商中平均分配。试求：(1)总产量、价格及两厂商的产量分别为多少(2)总利润增加多少(3)一方给另一方多少利润

如图是一个草原生态系统食物网简图，请分析下列问题：

小鸟与蝗虫的种间关系为（）