Meaning of off sick

Test No. [color=blue]incompl/inter-95 “Letter of Complaint (2)”, question 10

since there were a number of people sick.

(a) through
(b) for
© off
(d) under

Test No. [color=blue]incompl/inter-95 “Letter of Complaint (2)”, answer 10

since there were a number of people off sick.

Correct answer: © off

Your answer was: [color=red]incorrect
since there were a number of people under sick.
[size=200]_________________________[/size]

because they are sick they got the day off, Am I right?

Yes, they were absent from work because of sickness.[YSaerTTEW443543]

TOEIC listening, photographs: The bund Shanghai[YSaerTTEW443543]