first coat of plaster

例句：

1. 1.The first coat of plaster on the wall is a crucial step in the construction process.
   墙上第一次抹的灰是建筑过程中的一个关键步骤。
2. 2. The painter applied the first coat of plaster to the walls before painting them.
   画家在刷墙之前先涂了一层灰。
3. 3.The builder used the first coat of plaster to level the floor before laying down the tile.
   建筑师用第一次抹的灰来平整地板，然后铺设瓷砖。