grain-and-grass harvesting machines

例句：

1. 1.These machines are designed to efficiently harvest grain and grass.
   这些机器被设计用来高效地收割谷物和草。
2. 2. The farmers rely on these machines to save time and effort in the harvest process.
   农民们依靠这些机器来节省时间和努力在收割过程中。
3. 3.The machines have greatly improved the efficiency of crop harvesting in rural areas.
   这些机器大大提高了农村地区农作物收获的效率。