plough的現(xiàn)在分詞怎么變化

　　例句：

　　The field had been ploughed and planted with corn.

　　這塊地已犁過并種上了玉米。

　　There was not one inch of soil that was not under the plough.

　　沒有一寸土地未被開墾成耕地。

　　The more ploughing and weeding, the better the crop.

　　一分耕耘，一分收獲。