用所给词的适当形式填空。

1. Look! The boy _____ (tie) his shoes over there.

2. My mother _____ (cook) when my father was reading a newspaper.

3. There _____ (be)a class meeting this evening.

4. My father often _____ (drive) to work.

5. Danny _____ (live) in China for three years.

以下实验或操作不能达到目的的是

A．用溴水鉴别苯、乙醇、四氯化碳三种无色液体

B．为除去甲烷气体中的少量乙烯,可将气体通入KMnO₄溶液中

C．为除去乙酸乙酯中的少量乙酸,可向混合物中加入适量的饱和碳酸钠溶液后分液

D．用激光笔检验淀粉溶液的丁达尔现象