风险投资信托理财产品具有封闭期较短、收益低的特点。( )
参考答案：错
________ the working efficiency, the boss allows the employees to have a coffee break. [ ]
A. Improving
B. To improve
C. Having improved
D. Improved
计轴系统单一评估计算机可以连接（）个计数管头，监控（）个轨道区段。
