by earth
按土
We improved the farm land by spreading earth over the sand.
我们在沙上撒土,以此改良耕地。
with earth
与地球
Helfand added that tracking an asteroid is just the first step. The next step is prevention of a collision with Earth.
希尔芬迪补充道,追踪小行星仅仅是第一步工作,下一步工作是防止其与地球发生碰撞。
介词by with和on表示使用工具时的区分