flat interferometer

例句：

1. 1. The floor is made of a very flat material.
   地板是由一种非常平坦的材料制成的。
2. 2. Flatten the pizza before baking it.
   在烤之前将比萨饼压平。
3. 3. The car was parked on a flat piece of land.
   汽车停在一块平坦的土地上。