The Missouri drainage area covers one-sixth of the entire United States.
举一反三
- The Midwestern States Region is a vast area of generally flat land that covers much of the center of the United States.
- There are _____ states in the United States.
- The Constitution of the United States of America is the Supreme law of the United States.
- There are 50 stars on the national flag of the United States. They represent today's 50 States of the United States.
- 中国大学MOOC: There are ________________ (a number）states in the United States.