1. When I walked past his house,________________(我聽見他在彈鋼琴).
2. ________________(學生們應該從這里得出一條經驗):Don't be misled by false appearances.
3. Had ________________(要不是有水庫)we'd never have been able to beat the drought.
4. Man,no less than the lower forms of life,_______________(是演化過程的產物).
5. ________________(液體密度越大),the easier it is to float on it.