code: def fmt_sentence(text):
      
      text = text.strip()
      if len(text) == 0:  # if empty string, return it
          return text
      else:
          text = text.lower()  # lower all char
          # delete redundant empty space
          chunks = [chunk for chunk in text.split(" ") if len(chunk) >= 1]
          chunks[0] = chunks[0][0].upper() + chunks[0][1:]
          return " ".join(chunks)
docs: English sentence formatter. 
  
      First letter is always upper case. Example:
      "Do you want to build a snow man?"
  
      **中文文档**
  
      句子格式。每句话的第一个单词第一个字母大写。