The farmer heard the cow lowed and went to check on it.

农夫听到牛叫，便去查看。

I can't say before I check on it. But I suppose it is.

在查之前我不能肯定，不过我想是这样。

Keep a check on it, and put the drain plug back on when the oil has finished draining.

继续检查，并把排水管堵塞时，回到石油已完成排水。