be covered with 和be covered by 的区别

题目

be covered with 和be covered by 的区别
the wall seem to be covered witn the skin of a fish
it looks as if the stadium is covered by a gray net of steel
分析一下这两句

答案

be covered with 覆盖着...（强调状态）
be covered by 覆盖着...（强调动作）