a major difference of principle的用法和样例：
- A major has a crown on the shoulder of his uniform.
- I take this seriously. It's a matter of principle.
- A major difference is that there are no exchange fees and many of the inefficiencies of trading the underlying shares on the exchange are eliminated.
- Because of the elevation of the lake's surface compared with the river level downstream, a major difference in potential energy exists across a dam.