What is the answer to this riddle "I am twice in a week and once in a year what am I"

Read these lines from "an open boat" and answer the question. an open boat by alfred noyes see - quick - by that flash, where the bitter foam tosses,
 the cloud of white faces, in the black open boat,
 which of the end rhymes below matches the one in the last line of the excerpt? “he’s living, i know. but he’s numbed with the cold.” “and there are no voices or ghosts in that darkness.” “and wraps her loose hair round his breast and his throat.” “come. loosen your fingers. – o god, let me keep him! ”

Mr and mrs van daan murmur their welcome what are the playwrights indicating by using the word murmur?

What theme of antigone do the above events reflects