—Always look around________you cross the street,David.—OK,I know,Mom.A.untilB.beforeC.unless
He ______ would do great thins should not attempt them all alone.
It is ______ of a problem to be poor than to be dishonest.
The monkeys escaped ______ the zoo yesterday evening.
He doesn’t ______ to be a scientist.
I’d like to go with you, ______, my hands are full.