1. We can say a lot of things about those( )(毕生致力于诗歌的人): they are passionate, impulsive, and unique.
2. Mary couldn’t have received my letter, ( )(否则她上周就该回信了).
3. Nancy is supposed to ( )(做完化学实验) at least two weeks ago.
4. Never once ( )(老两口互相争吵) since they were married 40 years ago.
5. ( )(一个国家未来的繁荣在很大程度上有赖于) the quality of education of its people.