fixed retaining walls

例句：

1. 1. The fixed date for the meeting has been set.
   会议的固定日期已经确定。
2. 2. The weather is fixed, and we can't change it.
   天气是固定的，我们无法改变它。
3. 3. The company's policy is fixed, and there's no room for negotiation.
   公司的政策是固定的，没有商量的余地。