fixed variate

例句：

1. 1. The car was fixed by the mechanic before we left.
   在我们离开之前，汽车被技师修好了。
2. 2. We need to fix the door before we go inside.
   我们需要在进去之前修好门。
3. 3. The roof is fixed securely with metal plates.
   屋顶用金属板牢固地固定住了。