U.S. President Barack Obama ______ a speech at a dialogue with Chinese youth at the Shanghai Science and Technology Museum during his four-day state visit to China, Nov. 16, 2009.

While _________the topic of music in class, all the students show great interest in it.

填入下面横线处的语句，衔接最恰当的一组是（ ）无论什么景物，在太阳的强烈光线下，总有几分太清晰，太现实， 。简单地说，日光下的景物是散文，只能使我们兴奋；月下的景象是诗，它能使我们遐想、幽思。①给我们视觉的刺激太强。②而在晚间，一切景物的色调都暗淡了，轮廓也迷离了。③这只能使人由疲倦而厌恶。④物我都冥合了，诗化了。⑤在这种外静内闲的境地，我们喜悦，悠然，怡然。⑥我们的心弦便弛缓下去。

Please tell me ________ for the meeting yesterday．—Sorry．The traffic was bad．

What do you think has made Tom feel down—- ______ his seat in the election, I think.