If you don't understand something, you may research, study, and talk to other people _______ you figure it out.
because
though
until
since
He commanded that all the gates _____when it was getting dark in case thieves came in .
– When will the sports meeting be held? – It has been suggested the sports meeting ______ till the smog is not so severe.
(2013)If we a table earlier, we couldn’t be standing here in a queue.
If the dog hadn’t woken us, we wouldn’t have noticed the fire and it _____ to the house next door.
-I didn’t watch the program “Where are we going, Dad?” yesterday. -I _______, either, if my father hadn’t reminded me.