—I’d like to invite you to my birthday party this evening.—Thanks, but ____ I’ll have time I’m not sure at the moment.
Only under special circumstances ________ not to wear their school uniforms.
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.