principal left ideal

例句：

1. 1.The principal of the school is Mr. Smith.
   学校的校长是史密斯先生。
2. 2. She is a principal in the school.
   她在学校担任校长。
3. 3.The principal of the company has just announced the new policy.
   公司的总经理刚刚宣布了新政策。