the working efficiency,the boss allows the employees to have a coffee break.
A. Improving
B. To improve
C. Having improved
D. Improved
网友回答
A. Improving
(答案→)B. To improve
C. Having improved
D. Improved
解析： 考查非谓语动词的用法。根据题意可知，这里应用动词不定式表示目的。句意为：为了提高工作效率，老板同意职工喝杯咖啡休息一下。