A horrible thought _________ him when he was waiting for Tom in the airport: what if the plane from Malaysia had been hijacked(劫持)?
Reading offers only material of knowledge; without thinking, however, it’s hardly possible to make ____ we read ours.
Was it ____ it snowed last night ____ he didn’t come?
If you send the best wishes to your mother on Mother’s Day,____will give her a great surprise.
He sat quietly in the room,listening to the rain____the window.
Everyone stood up _____ the hero came into the lecture hall.