BY _____ TIME WE HAD JUST LEFT THE OFFICE, _____ ALARM WENT OFF.A....

16. - ARTICLES LI THUYET BAI TAP DAP AN
ARTICLES LI THUYET BAI TAP DAP AN
16. By _____ time we had just left the office, _____ alarm went off.A. / the B. a/ an C. a/ the D. the/ an