tar spot of grasses

例句：

1. 1. The farmer found a tar spot onhis horse's coat.
   农民在他的马身上发现了一个焦油斑点。
2. 2. The tarspot was caused by the oil spill inthe river.
   这个焦油斑点是由河流中的石油泄漏造成的。
3. 3. The tar spot onthe fence was a sign of neglect.
   围栏上的焦油斑点是忽视的标志。