依次填入下列各句横线处的成语，最恰当的一组是①他是一个心地善良的人，但性格懦弱、谨小慎微，做起事来总是_______，从来不敢越雷也一步。②当今世界科技突飞猛进，我们更要勇于开拓，不断进取，如果______，就会落后甚至被时代潮流所淘汰。③想让中国传统戏曲焕发出新的生命力，决不能满足于现状，_______，唯有创新才是弘扬戏曲文化的康庄大道．

will the meeting end一In half an hour.

As his son played a range of classical pieces from Mozart to Beethoven smoothly, the father swelled pride.

What do you think of __________ idea of taking part in ‘Earth Hour’—Wonderful! I’ve never heard of __________ one! We can reduce pullution in this way.

What are you ____