A question from an online English level test (https://antischool.online/cabinet/online-test/?utm_source=youtube&utm_medium=social-organic&utm_campaign=test&utm_content=ariz&utm_term=levels-01.06.21):
№9 -Online check-in should be ______(11) until you will ____ (12) at the airport so you'll chose the best seats.
-Of course! Thanks for your help!
A. complete; have arived
B. completed; arrive
C. completed; have arrived (seems to be the intended answer, because when it's changed, points are lost)
Is this sentence grammatically correct? What is the meaning of this sentence? Which answer is correct?
P.s. A free online lesson is offered to those who finish the test)))