have been是什么時態的標志

　　例句：

　　Severe winds have been battering the coast.

　　狂風一直在海岸肆虐。

　　At times they have been shamefully neglected.

　　有時他們被可恥地忽略了。

　　The marshes have been drained.

　　沼澤地里的水已排干。