positive symmetric operator

例句：

1. 1. The team's performance was positive.
   团队的表现是积极的。
2. 2.The new policy is positive for the economy.
   新政策对经济是有利的。
3. 3. The teacher gave a positive feedback on the student's work.
   老师对学生的工作给予了积极的评价。
4. 1. The design of the building is symmetrical.
   这栋建筑的设计是对称的。
5. 2. The two sides are symmetric in terms of their policies.
   在政策方面，两边是对称的。
6. 3. The flowers are arranged symmetrically on the table.
   桌子上的花摆放得很对称。
7. 1. The engineer is an operator at the factory.
   这位工程师是工厂的操作员。
8. 2. The operator must follow the safety procedures strictly.
   操作员必须严格遵守安全程序。
9. 3. The operator has to be familiar with the machine's operation.
   操作员必须熟悉机器的运作方式。