在下列句子的空缺处依次填入成语，最恰当的一组是（ ）①毒奶粉、地沟油、假羊肉等一系列____ 的事件接连发生，人们不得不反思：为什么我们的道德竟然沦落到了这样的地步②在离地球三百公里的太空课堂上，航天员王亚平一边做实验，一边___ ，为6000万中小学生上了一堂别开生面的科普课。③中国不差钱，只要能激活民间资本让银行资本难以____ 的灵活运作方式与潜能，“钱荒”问题就迎刃而解了。

ng earnedthe respect from the whole world as he hopped down the track to the finishingline, ____the last hurdle

I think _______ a foreign language is not easy. You should _______ it often.

The Shutes haven’t decided __________ to go there for a field trip this weekend.

30·You can make a complaint to the local government____ you are happy with the way things are