根据句意填写单词补全句子。

1. Beijing is the _____________ city of China.

2. I live in China, I speak _____________.

3. The U. S. is _____________ of Canada.

4. Tom lives in the U. S. He speaks _____________.

5. Canada's flag _____________ a leaf.

6. What _____________ is the flag of China?  It's red.

7. How many stars in the China's flag?  There are _____________ stars.

某企业正在讨论更新现有的生产线，有两个备选方案：A方案的净现值为400万元，内含报酬率为10%；B方案的净现值为300万元，内含报酬率为15%．据此可以认为A方案较好。 ( )