1. The planes had been planting seed for nearly a month when it began to rain.
    飞机撒播近一个月后，开始下起雨来。

2. They were getting things ready for this year´s tree-planting.
    为今年的植树做准备，

3. It has sponsored the growing of cash crops such as cassava, maize, cotton, and the planting of trees to regenerate waste land.
    为恢复荒地的地力，它资助人们种植诸如木薯、玉米、棉花之类的经济作物和植树造林。