Final answer:
The words in the excerpt that develop a mournful mood are bleak, dying, ghost, and sorrow.
Step-by-step explanation:
The words in the excerpt that best help develop a mournful mood are bleak, dying, ghost, and sorrow.
The word bleak describes a sense of desolation and hopelessness, contributing to the mournful mood. The word dying suggests loss and impending death, which adds to the melancholy atmosphere. The word ghost evokes a sense of the supernatural and the presence of departed souls, further enhancing the mournful tone. Lastly, the word sorrow directly conveys the feeling of deep sadness, intensifying the mournful mood of the excerpt.