1. We can say a lot of things about those who are devoted to poems in their whole lives (畢生致力于詩歌的人). They are passionate, impulsive and unique.

2. Mary couldn’t have received my letter, or she should have made a reply last week. (否則她上周就該回信了).

3. Nancy is supposed to have finished her chemistry experiment(做完化學(xué)實驗) at least two weeks ago.

4. Never once has the old couple quarreled with each other (老兩口相互爭吵)since they were married 40 years ago.

5. The prosperity of a nation depends largely on (一個國家未來的繁榮在很大程度上有賴于) the quality of education.