Read the extract given below and answer the questions that follow :
"In mist or cloud, on mast or shroud,
It perched for vespers nine;
Whiles all the night, through fog-smoke white,
Glimmered the white moonshine."
(a) Where were the Mariners ?
(b) Who is the'It' referred to in these lines ?
(c) What does 'vespers nine' mean ?
(d) Why was 'it' a boon for the sailors ?
