给定一段英文文本，请输出文本中出现最频繁的单词及其出现次数。注意，忽略大小写，同时需要清除标点符号和停用词汇（如"is","the","and"等）。


"This is a sample text to demonstrate the task of finding the most frequent words in a given piece of text. Hopefully, the result will be accurate and insightful!"
出现最频繁的单词是 "text"，出现了两次。