题目

The manager spoke highly fo such ____ as loyalty,courage and truthfulness shown by his employees.         A. virtues     B. features     C. properties     D. characteristics 答案：A 解析: virtues意为：美德；features 意为：特征；properties财产 ；characteristics（性格等方面）特征。杠杆的平衡状态是指杠杆处于_____或者_____状态。杠杆平衡的条件是当杠杆平衡时_____。