The plane takes off at 6:00 p.m. So I have to arrive at the airport ________ 5:30 p.m. at the latest.A after B. since C. until D. by
______ we had read your letter ______ the true state of affairs.
Take the medicine and have a good sleep, but if the pain continues, ______ your doctor.
The earlier settlers learned to farm the land through ______ and error.
The moment she heard of the news that her son was involved in the crime, she ______ pale.
I didn't see you at the meeting. If you ______ , you would have met my brother.