1. Man,no less than the lower forms of life，_______________（是演化过程的产物）.
　　2. _______________（不止一个人觉察到）her agitation.
　　3. ________________（液体密度越大）,the easier it is to float on it.
　　4. _______________（只有工人的要求得到满足）will they return to work.
　　5. Had ________________（要不是有水库）we'd never have been able to beat the drought.

　　答案与解析：
　　1. is a product of the evolutionary process
　　2. More than one person has noticed
　　3. The denser a liquid is
　　4. Only when the workers' demands are satisfied
　　5. it not been for the reservoir