—Does David often come to school ____ bus?—Yes, but sometimes he comes ____ his father’s car.
There is no ______ in trying to talk him into joining us. He enjoys being alone.
---But for your timely warning, we into great trouble. ---Well, you know we’re friends.
China’s third manned spaceship Shenzhou Ⅶ was launched and three pilots successfully ____ the mission.
Wind power is an ancient source of energy we may return in the near future.
It was not until dark ______ he found ___ he thought was the correct way to solve the problem.