答案： not to mention the youth
3．We expressed our grateful thanks to the local council，without whose help this meeting________________________ (不可能准时举行)．(hold)
答案： couldn’t have been held on time
4．______________________(据报道) air quality in this city has been improving since they replaced coal with oil and gas two years ago.(report)
答案： It is reported that
5．He ____________________(面临困境) of whether or not to return to his country after he got the doctor’s degree in America.
答案： was faced with the dilemma Ⅳ.话题写作
根据提示，利用本单元所学知识，完成下面的小作文并背诵成文。
1．科技的发展使他一直致力于的关于如何治愈人们的这种疾病的难题终于得到了解决。(wrestle with，all the time，figure out，cure)
2．他跟他的朋友通信，并邀请他加入到这个项目的研究中来。(correspond，meanwhile) 3．他的朋友向他表示祝贺并决定帮助他，利用科技的优势使这种方法更有效。(congratulate)
4．毫无疑问，他们的努力没有白费。(There is no doubt，in vain) 参考答案
The development of science and technology has made it possible for him to figure out the problem about how to cure people of the disease，which he had been wrestling with all the time.Then he corresponded with his friend；meanwhile he invited him to join in the research.His
friend congratulated him and decided to assist him，taking the advantage of science and technology to make the method more effective.There was no doubt that their effort was not in
vain.