5. 解析：选A。句意为：老师以为汤姆在埋头看书，而事实上他在睡觉。前后两句是对比关系， 故选A，此处while意为“然而”。

4. 解析：选A。上句的句意为：你错过了最有趣的部分。所以下句应会表示可惜。What a shame！表示“真可惜啊！”　

3. 解析：选B。ask的句式为：ask sb.　 to do sth.；appeal的句式为：appeal to sb.　 to do sth.;　 declare的句式为：declare to sb.+that?clause/to be+adj./n.; announce的句式为：announce to sb.+that?clause。appeal意为“呼吁”，故此处选B。句意为：红十字会正在呼吁大家竭尽全力向地震灾区捐献物品。

2. 解析：选B。考查短语辨析。make a promise 许诺;　 break one’s promise 食言; keep a promise 信守诺言; carry out a promise 履行承诺；根据句意可知选B。

5. In the interview,I found my voice trembling with nervousness.

提升练习

4. The telephone system has broken down, so I can’t get through.

3. Food is essential to life.

2. In the past thirty years, great changes have taken place in my hometown,making it take on a new look.