1. We can say a lot of things about those who are devoted to poems in their whole lives (毕生致力于诗歌的人). They are passionate, impulsive and unique.
2. Mary couldn’t have received my letter, or she should have made a reply last week. (否则她上周就该回信了).
3. Nancy is supposed to have finished her chemistry experiment(做完化学实验) at least two weeks ago.
4. Never once has the old couple quarreled with each other (老两口相互争吵)since they were married 40 years ago.
5. The prosperity of a nation depends largely on (一个国家未来的繁荣在很大程度上有赖于) the quality of education.