preliminary heating

例句：

1. 1. The preliminary heating of the new furnace is essential for its proper operation.
   新炉子的初步加热对于其正确运行至关重要。
2. 2.During the preliminary heating phase, the temperature should be gradually increased to avoid overheating.
   在预热阶段，温度应该逐渐升高，以避免过热。
3. 3. The preliminary heating process is crucial for ensuring the structural integrity of the building.
   初步加热过程对于确保建筑物的结构完整性至关重要。