plowing造句

The three main expeditions were plowing through seas infested with U - boats.
三个主要远征部队驶经充满潜艇的海岸.

It's all to no purpose; I tell you that you are plowing the sand.
这是徒劳无益的; 告诉你,你在枉费心机.

When plowing, I plowed deeply ; when weeding, I weeded throughout.
耕耘时深耕细锄, 除草务尽.