preheating by dielectric losses

例句：

1. 1.The oven needs to be preheated before baking the cake.
   烤蛋糕前需要预热烤箱。
2. 2.The machine needs to be preheated before it can operate properly.
   这台机器在能正常工作之前需要预热。
3. 3.Before starting the project, we need to preheat the materials.
   在开始这个项目之前，我们需要预热材料。