perhaps the most far-reaching has been the inexorable decline in thw scope and seriousness of their arts coverage.这里的has been the inexorable是不是现在完成进行时呢？如果是现在完成进行时为什么inexorable不是ing？
Of all the changes that have taken place in English language newspapers during the past quarter century, perhaps the most far-reaching has been the inexorable decline in the scope and seriousness of their arts coverage.
